Restoring AE86 w/ 4AGE 16v + HKS ITB + Haltech E6X

[jondee86]

According to this, I think I can use fuse #11 to go along with the intention
of the fuse. (Guage 7.5A) I'm also thinking this must be powered only when
IGN is ON. I'll double check.

You seem to have this covered !! If you have followed the instructions regarding
power supply to the sensor heater, controller and gauge, you should be fine. As
the heater does draw a little bit of current, it is often recommended to power this
from a key-switched supply separate from the controller and gauge.

It is also a common requirement to avoid the possibility of cold exhaust condensate
hitting a hot sensor at startup. This translates to starting the engine promptly when
the ignition is turned ON i.e. don´t wait until the sensor heats up and the gauge
begins reading before starting a cold engine... especially in winter.

Cheers... jondee86

PS: I am away from home on holiday at the moment, and don´t always have internet
access. But I will be checking on your progress when I can

[aceforever]

First of all, I was wondering how you were doing! I was imagining the worst things possible since you disappeared out of the blue. But! Luckily you're alive, well and ON VACATION! I could go for one of those, haven't had a vacation in a while. Thank you so much for taking the time to help me out, even on your vacation! I hope you have a wonderful time!
---

That cylinder appears to be the "Charcoal Cannister" that is used on the USDM
AE86 as part of the emissions control system. It´s task is to absorb gasoline fumes
venting from the gas tank while the engine is not running. The cannister incorporates
an air inlet (underneath I think?) with a one-way valve. There is a small outlet on
top that connects to a vacuum source on the inlet side of the engine... I´m not
sure exactly where.

When the engine starts, air is drawn in thru the one-way valve, thru the charcoal
picking up some of the absorbed fumes, and they get drawn into the engine intake
manifold and burned.

Ah, thanks for solving that mystery. I had a vague guess that it's related to the fuel lines and I'm glad it's true. I'll probably have to go through the manuals over again. I may have missed the pages about the charcoal canister, but I've looked through them a bunch of times. Maybe I can find pictures of how stock cars are set up to see where it's supposed to go and find out where I should hook it up.

The FPR maintains (controls) pressure between the outlet of the pump and the
inlet of the FPR. On the outlet of the FPR the pressure drops to close to atmospheric
in the return line to the tank. The FPR is pressure compensated by a small hose that
senses vacuum in the intake manifold. The idea is to maintain a constant pressure
differential across the fuel injectors by reducing the rail pressure as the manifold
pressure drops.

Yes. As you no longer have an inlet plenum to provide a vacuum signal for the FPR
the signal is taken from the vacuum box. In due course you will find that the ITB´s
do not generate a very strong vacuum signal, so the calibration of the FPR will be
incorrect. This is not a problem, as you can compensate for the difference in your
fuel map on the ECU.

Thanks for explaining the concept of the FPR to me. Does the ITBs not provide a good vacuum signal because of the multiple butterfly valves not creating a tight seal, what's the difference between a single throttle body and ITB that causes this? I'm also wondering why ITBs are designed using a vacuum box, is it to provide even vacuum within the multiple intake runners?

When the clutch master cylinder in an AE86 starts to leak, it is very common
for the fluid to leak to the inside of the car. Sometimes it will run down the
firewall under the carpet and make a wet patch on the floor. Clutch/brake fluid
is harmful to paint, so it would be worth confirming if the cylinder is leaking or
not. If it leaking, they are relatively inexpensive to replace.

I'm not familiar with the brake cylinder components. Is the cylinder connected to the center of the brake booster drum the master or is the one off to the side of the drum? RHD picture below, but it's similar enough I'm guessing?

How do I know if it's leaking? Does having liquid where the piston is inside the cabin mean that it's leaking? or is that the lubrication for the piston?

However, it does
help if you are a double jointed midget with small hands, and can stand on your
head for some time while finding the nut that hides way up under the dash

Hahahaha, tell me about it. I was running wires from the driver kick panel to the passenger kick panel and it was hours of laying upside down on the driver seat. My abs were pretty sore after the whole ordeal. Not looking forward to fixing this up but I don't like rust eating away at something I'm working hard for.

You seem to have this covered !! If you have followed the instructions regarding
power supply to the sensor heater, controller and gauge, you should be fine. As
the heater does draw a little bit of current, it is often recommended to power this
from a key-switched supply separate from the controller and gauge.

Interesting, I always thought that the 6PIN coming from the sensor hooked up to the controller and gets its power from there.
The PLX AFR controller uses this method.



It supposedly uses 7.5Watts, so some simple math reveals 0.625Amps. This shouldn't be too bad for the 7.5A fuse, but are you thinking it's not the most ideal place to tap power since a short in the controller/gauge/sensor can affect the others?

EDIT: You know what I could have done and saved myself the ab exercise is to use one of the provided +12V sensor wires coming from the Haltech Engine harness. Why didn't I think of that before!? *sigh*

EDIT2: Since the PLX Manual doesn't have much in terms of what to tap for power, I was reading LC-1 manuals and it says,

Circuits that share power with the vehicle’s stereo, ignition system, ECU, lighting, or fuel pump should not be used. When in doubt, create an additional circuit using an automotive relay available at any automotive parts supplier. See the next section for a relay installation diagram.

It's odd because the haltech harness has sensor +12V on the same circuit as the ECU DC in.

It is also a common requirement to avoid the possibility of cold exhaust condensate
hitting a hot sensor at startup. This translates to starting the engine promptly when
the ignition is turned ON i.e. don´t wait until the sensor heats up and the gauge
begins reading before starting a cold engine... especially in winter

Ah! so it's definitely good I wired this to IGN ON rather than ACC. I'll keep the starting quickly tip in mind. Curious, does this also apply to modern cars?

[jondee86]

Does the ITBs not provide a good vacuum signal because of the multiple butterfly
valves not creating a tight seal, what's the difference between a single throttle body
and ITB that causes this?

I have never seen a convincing explanation of exactly why ITB´s make less vacuum than a
single throttle setup. It is not related to butterfly sealing... but does seem to be related to
the volume of the inlet plenum. A typical ITB setup might idle at 80kPa absolute (mine does)
and a typical single throttle setup might idle at 34-40kPa absolute. This is why MAP sensor
load control works fine on single throttle engines, but ITB engines are usually setup with
TPS load control. On my engine the manifold pressure is at atmospheric (100kPa) from about
25% throttle opening, so MAP sensing for load control is ineffective at higher openings.

I'm also wondering why ITBs are designed using a vacuum box, is it to provide even
vacuum within the multiple intake runners?

The plenum chamber on a single throttle setup provides for smoothing of pulsations caused
by the individual cylinders inhaling, and provides a stable average vacuum reading. The small
volume of air behind the throttle on an ITB is subject to violent pressure fluctuations, and
any signal taken from a single inlet runner will have heavy pulsations. For this reason it is
usual to take a small diameter hose from each runner to a vacuum box (collector). The box
averages the signals and damps the pulsations to provide a stable signal for the FPR and MAP
sensor (if one is used).

I don´t like to see brake vacuum taken from the collector, or the signal tubes used for the
supply of idle control air. The FPR and MAP sensor are pressure only (no flow) whereas
the brake and ISCV functions require flow which will mess with the stability of the vacuum
sensed in the collector box.

I'm not familiar with the brake cylinder components. Is the cylinder connected to the
center of the brake booster drum the master or is the one off to the side of the drum?

The large metal "pancake" drum is the brake booster, and the brake master cylinder is
the part sticking out from the center. The smaller cylinder with a reservoir on top alongside
is the clutch master cylinder. The clutch slave is attached to the side of the bell housing
under the car. Below the brake master attached to the inner guard, you can see the brake
proportioning valve.

How do I know if it's leaking? Does having liquid where the piston is inside the cabin
mean that it's leaking? or is that the lubrication for the piston?

The actuating rod for the clutch master has a seal to keep fluid from leaking to the cabin.
If there is any sign of wetness there (and it is not just moisture condensation from the cold)
your master is leaking. Clutch/brake fluid is hygroscopic and when moisture gets into the
cylinder it forms corrosion. This corrosion wears and damages the seals to cause leaking.

... the 6PIN coming from the sensor hooked up to the controller and gets its power from
there.The PLX AFR controller uses this method.

If the PLX controller is setup to supply power to the sensor heater element, then you are
safe to use the wiring recommendations provided with the unit. WBO2 controllers and sensors
are incredibally sensitive and work with tiny voltages. This makes them sensitive to any
unwanted "noise" in the power supply (switching transients etc) and to ground loops. Most
of the problems I have read about come down to these two points. Therefore it is important
to follow the suppliers intructions explicitly for power supply and grounding.

The WBO2 sensor uses a combination of exhaust gas and electric heating to maintain the
sensor at the correct operating temperature. If a splash of condensation hits the hot ceramic
of the sensor, the ceramic may crack from thermal shock. The possibility of this happening
depends a lot on ambient temp, header material and design, sensor location etc. It is unlikely
to happen with a correctly located sensor (above the horizontal centerline of the exhaust,
and in a straight section). I start my car without any sensor warmup period, summer and winter,
and have never had a problem.

In the early days of WBO2 sensors they were widely considered to be only suitable for short-
term uses such as engine tuning. This was due to the sensors being susceptible to poisoning
by leaded fuels. However, these days they are fitted as standard equipment to many modern
cars and have life expectancies of 80-100,000 miles before changeout. Fast warmup engine
designs and correct sensor placement obviously helps.

Cheers... jondee86

PS: I can recommend the south of Brasil at this time of the year... if you don´t mind the
odd thunderstorm

[aceforever]

I have never seen a convincing explanation of exactly why ITB´s make less vacuum than a
single throttle setup. It is not related to butterfly sealing... but does seem to be related to
the volume of the inlet plenum. A typical ITB setup might idle at 80kPa absolute (mine does)
and a typical single throttle setup might idle at 34-40kPa absolute. This is why MAP sensor
load control works fine on single throttle engines, but ITB engines are usually setup with
TPS load control. On my engine the manifold pressure is at atmospheric (100kPa) from about
25% throttle opening, so MAP sensing for load control is ineffective at higher openings.

Had to read this a few times to understand. Let me see if I got this straight. So since the vacuum is weak on ITBs it's hard to know how much air is actually making into the cylinders based on MAP. Thus, people usually use TPS. Is the reading off or is there just actually less vacuum?

If I'm going to use TPS why would I use the MAP sensor at all?

The plenum chamber on a single throttle setup provides for smoothing of pulsations caused
by the individual cylinders inhaling, and provides a stable average vacuum reading. The small
volume of air behind the throttle on an ITB is subject to violent pressure fluctuations, and
any signal taken from a single inlet runner will have heavy pulsations. For this reason it is
usual to take a small diameter hose from each runner to a vacuum box (collector). The box
averages the signals and damps the pulsations to provide a stable signal for the FPR and MAP
sensor (if one is used).

I was close then!
You said that there are more violent pressure fluctuations behind the ITB. Is that why there are slots for injectors to pump fuel in there so the fuel gets atomized better?

I don´t like to see brake vacuum taken from the collector, or the signal tubes used for the
supply of idle control air. The FPR and MAP sensor are pressure only (no flow) whereas
the brake and ISCV functions require flow which will mess with the stability of the vacuum
sensed in the collector box.

That makes sense, so this means my MAP / FPR would be off somewhat since my collector has both signal tubes and booster connectors.

The large metal "pancake" drum is the brake booster, and the brake master cylinder is
the part sticking out from the center. The smaller cylinder with a reservoir on top alongside
is the clutch master cylinder. The clutch slave is attached to the side of the bell housing
under the car. Below the brake master attached to the inner guard, you can see the brake
proportioning valve.

Thanks for the clarification here!

The actuating rod for the clutch master has a seal to keep fluid from leaking to the cabin.
If there is any sign of wetness there (and it is not just moisture condensation from the cold)
your master is leaking. Clutch/brake fluid is hygroscopic and when moisture gets into the
cylinder it forms corrosion. This corrosion wears and damages the seals to cause leaking.

It is pretty wet on the actuating rod. I think I probably need to replace the master cylinder at some point. I found this post from the old forums. http://forums.club4ag.com/zerothread?id=62367 Does the steps there seem correct to you? Does OEM or aftermarket matter for these things?

If the PLX controller is setup to supply power to the sensor heater element, then you are
safe to use the wiring recommendations provided with the unit. WBO2 controllers and sensors
are incredibally sensitive and work with tiny voltages. This makes them sensitive to any
unwanted "noise" in the power supply (switching transients etc) and to ground loops. Most
of the problems I have read about come down to these two points. Therefore it is important
to follow the suppliers intructions explicitly for power supply and grounding

It only says:

Step Six
Connect power to the SM-AFR
Tip: Find and connect to 12-18v power source (We advise the ignition
switch.) A 5Amp fuse is recommended for safety.
DO NOT POWER UNIT UNTIL INSTALL IS COMPLETE.

I might just use the sensor +12V from the engine harness then. All the sensor power wires are under a circuit with 10A fuse though.

I powered the whole system up already without installing the sensor into the exhaust. I hope I didn't mess anything up there.

The WBO2 sensor uses a combination of exhaust gas and electric heating to maintain the
sensor at the correct operating temperature. If a splash of condensation hits the hot ceramic
of the sensor, the ceramic may crack from thermal shock. The possibility of this happening
depends a lot on ambient temp, header material and design, sensor location etc. It is unlikely
to happen with a correctly located sensor (above the horizontal centerline of the exhaust,
and in a straight section). I start my car without any sensor warmup period, summer and winter,
and have never had a problem.

In the early days of WBO2 sensors they were widely considered to be only suitable for short-
term uses such as engine tuning. This was due to the sensors being susceptible to poisoning
by leaded fuels. However, these days they are fitted as standard equipment to many modern
cars and have life expectancies of 80-100,000 miles before changeout. Fast warmup engine
designs and correct sensor placement obviously helps.

Didn't know these sensors were so sensitive back then. Good thing this is pretty flushed out it seems.

(coincidentally, my daily driver currently has an engine service light, plugged in an OBD2 reader and looked up the code saying O2 not operating at temperature. I hope it's just a dead sensor. But it's weird, I only have 42,000 miles on the car.)

PS: I can recommend the south of Brasil at this time of the year... if you don´t mind the
odd thunderstorm

Sounds exotic! I've only traveled around the US and sometimes venture out to Asian countries. Any points of interests you would recommend?

[aceforever]

I got replacement struts for my hatch but one side is giving me a lot of trouble. It looks older than the other side and I couldn't get the strut from the ball joint screw. I tried to use a 12mm wrench on it and I rounded off the stuck screw.



Sad times, one of my friends suggested to file off two sides so I can vice grip it.

[jondee86]

A typical ITB setup might idle at 80kPa absolute (mine does) and a typical single throttle setup
might idle at 34-40kPa absolute. This is why MAP sensor load control works fine on single throttle
engines, but ITB engines are usually setup with TPS load control. On my engine the manifold
pressure is at atmospheric (100kPa) from about 25% throttle opening, so MAP sensing for load
control is ineffective at higher openings.

Had to read this a few times to understand. Let me see if I got this straight. So since the vacuum
is weak on ITBs it's hard to know how much air is actually making into the cylinders based on MAP.
Thus, people usually use TPS. Is the reading off or is there just actually less vacuum?

If I'm going to use TPS why would I use the MAP sensor at all?

Your questions touch on some concepts that are important to understanding the differences
between TPS/RPM (Alpha-N) control and MAP/RPM control. MAP control is most successful on
single throttle engines where the inlet manifold pressure is a good indication of the quantity of
air being drawn into the engine. The MAP reading will provide a decent range where the pressure
varies with flow, allowing the ECU to scale fueling and adjust spark accordingly.

ITB´s have a much smaller range where pressure varies with flow. Using the examples given above,
you can see that the pressure reaches atmospheric at a small throttle opening, making it nearly
impossible to achieve proper load control using MAP as a reference. Essentially, this situation comes
about because ITB´s are sized for maximum flow at high rpm´s and are over-sized for low rpm
operation. The AE101 20V overcomes this problem by using an AFM which does provide a decent
signal proportional to airflow, but the ITB´s must be run in an airbox (plenum) with the AFM on
the entry to the plenum to measure TOTAL airflow.

By using a TPS mounted on the throttle linkage, a signal proportional to throttle opening can be
derived without any reference to MAP. The TPS signal will be linear whereas the airflow thru the
throttles is not, but none-the-less it can be used by the ECU to calculate fuel and spark, as the
maps themselves are fully programmable. The engine will run without any MAP reference, and many
modified engines run perfectly well on TPS/RPM control.

However, there is a small control zone at idle and at very small throttle openings where MAP control
can work on ITB engines. And current model programmable ECU´s are able to take advantage of
this small zone of superior control by using a blend of TPS and MAP control. Idle and just off idle
running is controlled from a MAP signal, and as the throttle continues to open, the ECU seamlessly
changes to TPS control. Obviously, for this work not only must you have an ECU with TPS/MAP
blending capability, but also a MAP sensor correctly mounted with a properly averaged connection
to all four intake runners.

Kind of long winded I know, and there is a lot more to this topic than I have written !!! But sometimes
it helps to have a bit of an overview to help put the pieces together.

Cheers... jondee86

[jondee86]

I don´t like to see brake vacuum taken from the collector, or the signal tubes used for the
supply of idle control air. The FPR and MAP sensor are pressure only (no flow) whereas
the brake and ISCV functions require flow which will mess with the stability of the vacuum
sensed in the collector box.

That makes sense, so this means my MAP / FPR would be off somewhat since my collector
has both signal tubes and booster connectors.

This is not something to get hung up about. Many people take the booster vacuum from
the vacuum box. The only downside is that using the brakes may result in an unwanted blip
in the MAP signal. But as you most likely will not be using a MAP sensor, that is irrelevant.

The actuating rod for the clutch master has a seal to keep fluid from leaking to the cabin.
If there is any sign of wetness there (and it is not just moisture condensation from the cold)
your master is leaking. Clutch/brake fluid is hygroscopic and when moisture gets into the
cylinder it forms corrosion. This corrosion wears and damages the seals to cause leaking.

It is pretty wet on the actuating rod. I think I probably need to replace the master cylinder
at some point. I found this post from the old forums. http://forums.club4ag.com/zerothread?id=62367
Does the steps there seem correct to you? Does OEM or aftermarket matter for these things?

Sounds reasonable. I have only worked with RHD cars and there is one nut to take off on
the engine side of the firewall, and one nut on the cabin side. No need to touch the brake
booster. As said, a geared wrench in the correct size would speed things along.

If the PLX controller is setup to supply power to the sensor heater element, then you are
safe to use the wiring recommendations provided with the unit. WBO2 controllers and sensors
are incredibly sensitive and work with tiny voltages. This makes them sensitive to any
unwanted "noise" in the power supply (switching transients etc) and to ground loops. Most
of the problems I have read about come down to these two points. Therefore it is important
to follow the suppliers instructions explicitly for power supply and grounding

It only says:
Step Six
Connect power to the SM-AFR
Tip: Find and connect to 12-18v power source (We advise the ignition
switch.) A 5Amp fuse is recommended for safety.
DO NOT POWER UNIT UNTIL INSTALL IS COMPLETE.

I might just use the sensor +12V from the engine harness then. All the sensor power wires
are under a circuit with 10A fuse though. I powered the whole system up already without installing
the sensor into the exhaust. I hope I didn't mess anything up there.

I would imagine that the PLX designers took care to make the controller suitable to use with
a single power supply and a single ground. Any clean power supply and solid ground that is
not shared with high current equipment should be fine.

It will not be harmful to power up the controller with sensor attached, but not installed in the
exhaust. However, there will probably be a recommended start-up and calibration procedure
for the WBO2 system, and you should follow this to ensure correct operation on the vehicle.
For example, the LC-1 requires the system to be first powered up with the sensor unplugged,
and then powered up again with the sensor plugged in but out of the exhaust for a "clean air"
calibration prior to the first engine start.

Cheers... jondee86

[aceforever]

Your questions touch on some concepts that are important to understanding the differences
between TPS/RPM (Alpha-N) control and MAP/RPM control. MAP control is most successful on
single throttle engines where the inlet manifold pressure is a good indication of the quantity of
air being drawn into the engine. The MAP reading will provide a decent range where the pressure
varies with flow, allowing the ECU to scale fueling and adjust spark accordingly.

ITB´s have a much smaller range where pressure varies with flow. Using the examples given above,
you can see that the pressure reaches atmospheric at a small throttle opening, making it nearly
impossible to achieve proper load control using MAP as a reference. Essentially, this situation comes
about because ITB´s are sized for maximum flow at high rpm´s and are over-sized for low rpm
operation. The AE101 20V overcomes this problem by using an AFM which does provide a decent
signal proportional to airflow, but the ITB´s must be run in an airbox (plenum) with the AFM on
the entry to the plenum to measure TOTAL airflow.

By using a TPS mounted on the throttle linkage, a signal proportional to throttle opening can be
derived without any reference to MAP. The TPS signal will be linear whereas the airflow thru the
throttles is not, but none-the-less it can be used by the ECU to calculate fuel and spark, as the
maps themselves are fully programmable. The engine will run without any MAP reference, and many
modified engines run perfectly well on TPS/RPM control.

This is very interesting. I think I understand a little more about this. Thanks for explaining this to me. I really appreciate it.

However, there is a small control zone at idle and at very small throttle openings where MAP control
can work on ITB engines. And current model programmable ECU´s are able to take advantage of
this small zone of superior control by using a blend of TPS and MAP control. Idle and just off idle
running is controlled from a MAP signal, and as the throttle continues to open, the ECU seamlessly
changes to TPS control. Obviously, for this work not only must you have an ECU with TPS/MAP
blending capability, but also a MAP sensor correctly mounted with a properly averaged connection
to all four intake runners.

I think the Haltech has a form of this TPS/MAP blending, not sure if it's good at all.

From the manual:

5.3.6 Zero Throttle Map
The zero throttle map is accessed through the menu structure under the maps menu.
The zero throttle map is used with engines that use Manifold pressure load sensing but cannot
produce a stable manifold pressure signal at idle. The zero throttle map is used when the
throttle position reads 0% and applies a set amount of fuel in place of the fuel quantity
normally extracted for the base fuel map. The map has 16 bars distributed across engine
speed in the range 0rpm to 2000rpm and each bar represents a quantity of fuel measured in
milliseconds.

5.3.7 Full Throttle Map
The full throttle map is accessed through the menu structure under the maps menu.
The full throttle map is used with engines that use Manifold pressure load sensing but cannot
produce a stable manifold pressure signal at full throttle. The full throttle map is used when
the throttle position reads higher than “Full Throttle Threshold” (refer to 4.2.2 Fuel Set-up
Page, p38) and applies a set amount of fuel in which the ecu will inject, regardless of the fuel
quantity normally extracted for the base fuel map. The map has 32 bars distributed across
engine speed in the range 0rpm to 16000rpm and each bar represents a quantity of fuel
measured in milliseconds.

The "Full Throttle Map" allows you to define a point where it should switch from MAP pressure to TPS. I assume this would be something to try AFTER I get everything working with normal TPS tuning?

Kind of long winded I know, and there is a lot more to this topic than I have written !!! But sometimes
it helps to have a bit of an overview to help put the pieces together.

Oh not at all. I'm really interested in learning about this type of stuff! Keep them coming!

[aceforever]

This is not something to get hung up about. Many people take the booster vacuum from
the vacuum box. The only downside is that using the brakes may result in an unwanted blip
in the MAP signal. But as you most likely will not be using a MAP sensor, that is irrelevant.

I see, I'll not worry about this for now. When the time comes to optimize the setup I hope I know more about if this bothers me or not.

Sounds reasonable. I have only worked with RHD cars and there is one nut to take off on
the engine side of the firewall, and one nut on the cabin side. No need to touch the brake
booster. As said, a geared wrench in the correct size would speed things along.

Cool. Sounds not so bad! I just need to find a replacement part. In the mean time, I'll have to watch out for leaks.

I would imagine that the PLX designers took care to make the controller suitable to use with
a single power supply and a single ground. Any clean power supply and solid ground that is
not shared with high current equipment should be fine.

The 7.5A Gauge fuse connects to oil level, fuel level and warning light, meter temp level, tach level, brake light.
I think you mentioned before that the tach takes a high EMP signal from the igniter. Do you think this would be an issue?

It will not be harmful to power up the controller with sensor attached, but not installed in the
exhaust. However, there will probably be a recommended start-up and calibration procedure
for the WBO2 system, and you should follow this to ensure correct operation on the vehicle.
For example, the LC-1 requires the system to be first powered up with the sensor unplugged,
and then powered up again with the sensor plugged in but out of the exhaust for a "clean air"
calibration prior to the first engine start.

Great! The product spec says "No Calibration Required" or maybe it has that warning because it's auto calibrating at initial start up?

[jondee86]

WBO2 Setup
Hook it up as you suggest. PLX is the latest generation of WBO2 and will have
protection circuitry built-in. As you say, it will most likely self-calibrate on start-up.

Clutch Master Cylinder
Generic product is fine. You should be able to pick one up from any auto parts store.

Idle Fueling
Because of the low airflow into the engine at idle, it is difficult to get a stable MAP
sensor reading. There is a lot of pulsation, and this causes the MAP reading to jump
around, altering the fueling, which in turn causes the rpm to fluctuate. The remedy
suggested by Haltech is to use "fixed" fueling for closed throttle idling.

WOT Fueling
Likewise, at full throttle and high throttle openings, the manifold pressure will be
at atmospheric, meaning that the MAP sensor can no longer respond to changes in
throttle position. To make sure that the fueling continues to increase right up to
WOT (past the point where the MAP sensor is already maxed out), Haltech again
recommend fixed fueling.

Note that these adjustments only apply to an engine using MAP load sensing.

TPS/RPM Fuel Mapping
When using TPS fuel mapping, the load scale varies from zero% (closed throttle) to
100% (WOT). The RPM scale varies from zero to a value higher than your expected
maximum rpm (say 10,000rpm). The software for the ECU will display a matrix of
LOAD vs RPM so that if you have 10% load increments and 1000rpm speed increments,
you will have 11 x 11 = 121 cells into which fuel values may be entered.

The ECU may use some closed loop auto-tuning method to populate the cells, or you
can enter fuel values manually. Once the cells are populated with reasonable values,
you can choose to either continue to run the engine in closed loop, or lock the fuel
values in place, and run the engine in open loop. You have full control of the fueling
in each of the 121 cells on your fuel map.

Cheers... jondee86

[aceforever]

Idle Fueling
Because of the low airflow into the engine at idle, it is difficult to get a stable MAP
sensor reading. There is a lot of pulsation, and this causes the MAP reading to jump
around, altering the fueling, which in turn causes the rpm to fluctuate. The remedy
suggested by Haltech is to use "fixed" fueling for closed throttle idling.

So is the sweet spot for MAP sensor usage between idle and 25% throttle (or whatever the reading is before atmospheric)?

TPS/RPM Fuel Mapping
When using TPS fuel mapping, the load scale varies from zero% (closed throttle) to
100% (WOT). The RPM scale varies from zero to a value higher than your expected
maximum rpm (say 10,000rpm). The software for the ECU will display a matrix of
LOAD vs RPM so that if you have 10% load increments and 1000rpm speed increments,
you will have 11 x 11 = 121 cells into which fuel values may be entered.

The ECU may use some closed loop auto-tuning method to populate the cells, or you
can enter fuel values manually. Once the cells are populated with reasonable values,
you can choose to either continue to run the engine in closed loop, or lock the fuel
values in place, and run the engine in open loop. You have full control of the fueling
in each of the 121 cells on your fuel map.

Are the injectors the only thing I'd need to think about when tuning an engine? Does ignition timing play a role here if I'm running the stock distributor/coil set up? I'll have to re-read the Haltech manual for the whole tuning process.

I was also wondering, since the ITBs don't have a hole for idle, does that mean I should prop open the butterfly valve open a little bit to start off? There is a screw that prevents the the controller arm from closing all the way, I'm guessing that's the screw I need to turn in order to adjust the idle throttle position. Changing this means I also need to recalibrate the 0% since I'm basically changing the 0% for when there's no human input.

[aceforever]

Good news! I ordered some parts off of ebay and I just got them! The swivel for the folding assembly is firm. It needs a new coat of paint that I'll work on later along with the rest of the body parts.


Haha I hope they work! My car has 1 OEM side mirror on the right side, and this somewhat hideous F1 style side mirrors on the left. Any aero advantage that I gain from doesn't outweigh how ugly I think they are.

[aceforever]

I haven't opened up an engine before, so when I first took one of the cam covers off I was surprised how dirty it is in there.


I decided to clean the part with some engine degreaser. Was this the right thing to do? Here's some in-progress picture.



I wonder how I should repaint them. It's a pretty sore sight at the moment since the OEM paint is chipping off.

[jondee86]

Idle Fueling
So is the sweet spot for MAP sensor usage between idle and 25% throttle (or whatever
the reading is before atmospheric)?

Not exactly a sweet spot, but it is the zone where the MAP reading responds to throttle
movement. It is in fact possible to control ITB´s from a MAP sensor, but the car will not
be nice to drive unless you do some clever things with the fuel map. I actually tried it
for a while, until I discovered that TPS gave a much better result.

Are the injectors the only thing I'd need to think about when tuning an engine?
Does ignition timing play a role here if I'm running the stock distributor/coil set up? I'll have
to re-read the Haltech manual for the whole tuning process.

The Haltech will also require the setting up of an ignition map on a TPS/RPM matrix. The
manual should walk you thru the process.

I was also wondering, since the ITBs don't have a hole for idle, does that mean I should
prop open the butterfly valve open a little bit to start off? There is a screw that prevents
the the controller arm from closing all the way, I'm guessing that's the screw I need to turn
in order to adjust the idle throttle position. Changing this means I also need to recalibrate
the 0% since I'm basically changing the 0% for when there's no human input.

One of your pictures showed what appeared to be the OEM idle control valve, detached
from the OEM single throttle body, and jury-rigged to connect to various tubes. This would
seem to be an (awkward) attempt to replicate the OEM system for supplying extra air to
raise the idle on cold starts.

There are other ways of dealing with idle air, but to keep things simple, I think you should
go with the plan you outline. Use the screw that opens all four throttles simultaneously, and
re-calibrate the TPS. Note that the throttle only need to be cracked open a tiny amount to
allow in sufficient air for idle.

Cheers... jondee86

[aceforever]

Wait, is it this thing?

[aceforever]

Haha I remember now,

That thing is the thermostatic idle-up valve that usually is bolted to the
underside of the OEM single throttlebody. It has been surgically removed
and grafted onto some kind of custom manifold block. Hot water from the
engine cooling system circulates around the valve causing it to close as
the engine warms up. When cold, it is open and allows extra air into the
engine to raise the cold idle speed. As the engine warms up the valve
greadually closes bringing the idle down to normal warm idle.

Is there harm in leaving that in place for now? It looks like it hooks up to the engine and I'd rather not work on coolant plumbing until I know the engine runs.

[jondee86]

Is there harm in leaving that in place for now? It looks like it hooks up to the engine
and I'd rather not work on coolant plumbing until I know the engine runs.

Actually, it looks to be a designed solution, so by all means leave it in place.
There should be two small hoses that connect to cooling water hard lines that
run along the inlet side of the engine under the ITB´s. Then you have the idle
air intake with the filter attached, and a hose that delivers idle air to the engine.
Theoretically, it should do this by splitting into four separate hoses, one of which
connects to each inlet runner.

By way of clarification, the ISCV supplies only extra air at start-up on the single
throttle engine, plus a small amount of leakage when closed (engine up to operating
temp). There is a separate screw-controlled by-pass for the bulk of the idle air
incorporated into the throttle body. I would guess that there may be something
equivalent on your "custom" setup ? Is there any kind of adjusting screw hidden
around the back of the box ?

Cheers... jondee86

[aceforever]

Is there any kind of adjusting screw hidden around the back of the box ?

I took another picture of the contraption. Is this a Toyota part? or a HKS part, or something totally different?



The yellow text "adjustment bolt" was only a guess. based on the physical location it look like as if it controls the engine coolant rate?

[aceforever]

Update:

Calibrated throttle without idle gap. Hopefully the ISCV works as intended.

O2 sensor installed. The actual install wasn't so bad, but it was pretty scary being underneath the car even with jack stands supporting the car. Everything wired up here, since the ECU only understands narrowband and the engine isn't running the gauge displays "AIR" and all red LED. I connected the analog narrowband wire to the ECU however it doesn't provide any reading other than 4 mV. I'm not sure if this is the normal behavior or something wasn't set up correctly. I'll need to wait until the engine is actually running to test if ECU is getting this.

Couldn't find the coolant temp connector, but found a TVIS actuator connector laying around and it's the same shape! Wired up according to the the electrical diagrams and ECU now reads coolant temp. Coolant reads a bit higher than air temp, hopefully this is normal too?



On the list:
Figure out what fuel map/ignition map to use. Understand what acceptable ranges for air fuel mixture for the 4age
Figure out what other ECU settings to make
Finalize fuel filter to fuel rail fittings with copper washers
Clean up cam covers and reinstall
Reinstall water pump/fan pulley and fan and connect up the fan belt
Lubricate the cams area with engine oil
Lubricate cylinders with transmission oil (an employee at an auto parts store recommended this)
Turn over the engine a few times by hand

Anything else I should do before starting the engine? I haven't checked on the spark plugs yet, I'm guessing I'll need a new set since it was sitting for a long time.

[jondee86]

I took another picture of the contraption. Is this a Toyota part? or a HKS part, or something totally different?

The top part is the standard Toyota thermostatic idle-up valve from the single throttle.
The underneath part looks like it could have been part of the HKS kit. The interesting
thing is that the hose goes to the vacuum box, which indicates that the vacuum sensing
hoses are also being used to supply idle air to the ITB´s. I´ve seen this done on other
engines to save duplicating the vacuum sensing and idle air connections to the throttles.

Basically, idle air for the engine is made up from butterfly leakage (fixed), leakage past
the thermostatic idle-up valve (fixed when engine up to temp) and an adjustable by-pass
valve on the OEM single throttle (fixed after idle set). It is possible that an orifice or some
extra clearance has been provided inside that lower chamber to provide the correct total
amount of idle air. No big thing... one of the capped off tubes on the idle up valve can
be un-capped if needed to provide a bit more air.

Cheers... jondee86

[jondee86]

O2 sensor installed. The actual install wasn't so bad, but it was pretty scary being underneath the
car even with jack stands supporting the car. Everything wired up here, since the ECU only understands
narrowband and the engine isn't running the gauge displays "AIR" and all red LED. I connected the analog
narrowband wire to the ECU however it doesn't provide any reading other than 4 mV. I'm not sure if this
is the normal behavior or something wasn't set up correctly. I'll need to wait until the engine is actually
running to test if ECU is getting this.

Seems normal enough. Gauges treat Full Lean (nothing but air) differently... some display a value and
yours says AIR. And at Full Lean the simulated output will be at some minimum value, so 4mV is not out
of order. Probably not worth pulling the sensor out to test it with a rag soaked in gasoline... just see what
it does when you start the engine.

A new set of spark plugs is always a good idea. Just get NGK copper core... don´t waste your money on
the Kryptonite tipped type. Clean and new and correctly gapped is all you need.

Cheers... jondee86

[aceforever]

The top part is the standard Toyota thermostatic idle-up valve from the single throttle.
The underneath part looks like it could have been part of the HKS kit.

Ah, see, I didn't even know that the top part is standard. The label on it is all worn out. Thanks for identifying this!

The interesting
thing is that the hose goes to the vacuum box, which indicates that the vacuum sensing
hoses are also being used to supply idle air to the ITB´s. I´ve seen this done on other
engines to save duplicating the vacuum sensing and idle air connections to the throttles.

I was thinking that too. That's why I was sort of concerned with the MAP readings earlier because you mentioned this is subject to brake booster and idle noise.

one of the capped off tubes on the idle up valve can
be un-capped if needed to provide a bit more air.

Ah, so maybe I should make my own adjustment system with the extra air tube if necessary.

[aceforever]

Probably not worth pulling the sensor out to test it with a rag soaked in gasoline

I didn't think of that! Very clever. I'll wait to see if I have to do that. It's a pain to crawl underneath the car.

A new set of spark plugs is always a good idea. Just get NGK copper core... don´t waste your money on
the Kryptonite tipped type. Clean and new and correctly gapped is all you need.

So a bunch of sites like amazon and oriely auto parts stores stock .044in copper cores but not .043in

I searched around and people are saying either that it's better to be safe, or it's so minute it's fine.

The manual says 1.1mm / .043in . Since this is a non-american engine, the engineers probably measured things in metric units. Converting 1.1mm to in yields .0433etc... so I'll be .007in off if I use .044in. I'll probably just go pick up a set of .044 and re-gap if necessary since that's the only ones they stock.

[aceforever]

Just pulled out the spark plugs currently in the engine. They weren't torqued at all for some reason as I could turn them by hand and take them out. These spark plugs use 5/8" socket. Weird that they don't use metric measurements on these.



Looks like NGK R BCPR5EY http://ngk-sparkplugs.com/bcpr5ey11-p-1838.html

Seems like they're NGK standard (I'm guessing these are the copper ones you speak of) .044in / 1.1m

I heard you can tell how healthy an engine is based on the spark plugs. Seems like cylinder 2 has a ton more carbon build up than the others. Cylinder 4 seems like it's the "healthiest"?

[jondee86]

BCPR5EY11 are the standard NGK copper core, resistor, 1.1 gapped plug for the JDM AE86.
They are as good as you will get and available at reasonable cost. I have used them for years

It is possible to tell something about the health of an engine by examining plugs pulled fresh
after a highway run, or even after a few weeks of normal round town running. However, you
won´t really learn much by diagnosing the plugs from an engine that hasn´t run in years, when
you can´t even be sure that the plugs were put back in the same cylinders they were in the
last time the engine was running.

Cheers... jondee86

[jondee86]

Thought I would touch on this topic as soon you will be wanting to turn the key and see
if you can get the engine to make some noise

It is difficult, if not impossible, to get a cold engine to start with the same fueling and
ignition timing that the engine uses for normal warm running. Cranking speed will be
around 250rpm which means air velocity in the intake runners will be low, allowing fuel
droplets to fall out of the airstream. The inlet runners will be cold causing fuel to condense
on the runner walls. The standard ignition advance of around 15deg at idle is not optimum
for an engine turning at 250rpm, and the standard warm engine idle air quantity will be
too low to sustain the operation of a cold engine.

So in a nutshell, successful starting of a cold engine requires...
- Extra air
- Extra fuel
- Less ignition advance

Extra Air on the 16V AE86 is provided by the thermostatic idle-up valve being open, and
raising cold idle to around 2200rpm. On factory 20V engines it is provided by the ECU driving
the ISCV wide open for starting.
Extra Fuel on the 16V AE86 is provided by the cold start injector, and on the 20V by the ECU
holding the injectors open longer for starting.
Less Ignition Advance AFAIK both the 16V and the 20V retard the ignition timing to around
10deg for easier starting.

Note that your great-grandpappy probably drove a car with MIXTURE Rich/Lean and IGNITION
Advance/Retard levers mounted on the steering wheel. And your pappy would have known that
pumping the gas on the family car helped it get started on cold mornings. These days the
adjustments are handled by the ECU and make for easy starting hot or cold.

Cheers... jondee86

[aceforever]

BCPR5EY11 are the standard NGK copper core, resistor, 1.1 gapped plug for the JDM AE86.
They are as good as you will get and available at reasonable cost. I have used them for years

Great! I just purchased a set of 4 from a nearby auto parts store for $10. They're so cheap!

It is possible to tell something about the health of an engine by examining plugs pulled fresh
after a highway run, or even after a few weeks of normal round town running. However, you
won´t really learn much by diagnosing the plugs from an engine that hasn´t run in years, when
you can´t even be sure that the plugs were put back in the same cylinders they were in the
last time the engine was running.

You make a good point! I don't even know if the sparks were used with the same engine. Better to put new ones in and see what shows up after driving.

[aceforever]

Thought I would touch on this topic as soon you will be wanting to turn the key and see
if you can get the engine to make some noise

I've been waiting for that for months! I'm afraid of turning the ignition to start since it feels like I only know a tiiiiiny amount of information. Thanks for helping me along the way!

The haltech manual suggests to crank the engine without fuel to check for trigger input and RPM reading. Is that harmful to the engine to crank like that, should I wait X amount of time before re-trying things if I don't get it right the first time? I wonder if the engine oil gets circulated when it's cranking. I'm guessing yes.

It is difficult, if not impossible, to get a cold engine to start with the same fueling and
ignition timing that the engine uses for normal warm running. Cranking speed will be
around 250rpm which means air velocity in the intake runners will be low, allowing fuel
droplets to fall out of the airstream. The inlet runners will be cold causing fuel to condense
on the runner walls. The standard ignition advance of around 15deg at idle is not optimum
for an engine turning at 250rpm, and the standard warm engine idle air quantity will be
too low to sustain the operation of a cold engine.

So in a nutshell, successful starting of a cold engine requires...
- Extra air
- Extra fuel
- Less ignition advance

Extra Air on the 16V AE86 is provided by the thermostatic idle-up valve being open, and
raising cold idle to around 2200rpm. On factory 20V engines it is provided by the ECU driving
the ISCV wide open for starting.
Extra Fuel on the 16V AE86 is provided by the cold start injector, and on the 20V by the ECU
holding the injectors open longer for starting.
Less Ignition Advance AFAIK both the 16V and the 20V retard the ignition timing to around
10deg for easier starting.

Note that your great-grandpappy probably drove a car with MIXTURE Rich/Lean and IGNITION
Advance/Retard levers mounted on the steering wheel. And your pappy would have known that
pumping the gas on the family car helped it get started on cold mornings. These days the
adjustments are handled by the ECU and make for easy starting hot or cold.

Ah, so I should set my ign timings to 15deg adv for normal operation, and 10deg for idle? I'll have to check up on the manual for if there's a setting for that. I don't think the ECU gets ignition switch STA though. I wonder how it'll know when it's starting or not. Or perhaps that doesn't even matter as maybe it uses coolant temp to calculate the ign timing? Probably need to also play with the inj settings too and hope the idle-up device works as intended.

P.S. I wish my great-grandpappy drove cars! (I'm probably romanticizing the old classics now haha) At some point I'd like to dig into how carburetors work but that's another adventure for another time.

My dad drove around an old 1985ish Honda Accord CA Hatchback back in my childhood. It was old, didn't go into fifth gear, the windows got super foggy. But it brings back good memories.

Seem familiar? We had it in white + black mouldings so it was almost a panda Trueno! I think this is probably why I fell in love with the Trueno since it was a childhood car PLUS RWD Plus panda scheme is so different from the car paint schemes nowadays.

We also had a 1990ish Toyota Corolla E90 (funny enough I drive a BMW E90 now). Is the "A" in "AE86" the sport version? Seems like most corollas in the US start with E## for chassis number. EDIT: Quick googling reveals that it's the engine code, makes sense.


There's an ugly Chrysler K car somewhere in my childhood car history. And possibly a 80s/90s Tercel at some point. I don't remember as they weren't very spectacular by any means.

[aceforever]

When I was hooking up the coolant temp sensor for the ECU, I noticed there was a brown temp sensor there too. What's that usually used for? ISCV? fan?

Speaking of fans, should I be bolting up the fan to the water pump pulley? It seems kind of archaic since modern fans are electric. I guess I can upgrade to electric later.

[jondee86]

When I was hooking up the coolant temp sensor for the ECU, I noticed there was a brown
temp sensor there too. What's that usually used for? ISCV? fan?

That´s the thermo-time switch for the cold start injector... now redundant.

Speaking of fans, should I be bolting up the fan to the water pump pulley? It seems
kind of archaic since modern fans are electric. I guess I can upgrade to electric later.

The engine driven fan is there to provide airflow thru the radiator when the car is stuck
in traffic or idling for long periods. It has some kind of wax or silicone fluid inside the hub
that allows the fan to free-wheel when cold, but engage when the engine gets hot. It works
effectively and reliably without any electrical input.

Converting to an electric fan is a common, but usually unnecessary modification.

Cheers... jondee86