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

[aceforever]

Do ITBs actually make less power than the stock manifold if everything else is the same?

Interesting question, and one on which everyone has an opinion. ITB´s have a much smaller volume
of air between the throttle plate and the inlet valves, and this provides for a sharper response when
the throttle is snapped open. On the downside, the shorter inlet runners and lack of a plenum are
said to reduce the power at lower rpm´s. Generally speaking, ITB´s do their best work at high rpm´s
where the larger total throttle area and shorter, more direct inlet path contribute to improved flow.

As I mentioned elsewhere, many, if not most ITB installations are oversized. Referring to the Jenvy
site you will see that for the 4AGE 38mm dia ITB´s would be all that is required, and would have better
control authority than the ST or BT ITB´s commonly used. Because of the higher flow capability of ITB´s,
modifications aimed at getting more air thru the engine are desirable... cams and a free-flowing
exhaust system will help here. At this point bumping up the compression will give good results.

As to your other question... cams and adjustable cam pulleys are higher cost items and readily able
to be sold. Either the previous owner did not get round to purchasing them, or they were removed
and replaced with the stock items.

Oh yeah... for what it is worth, I am using ST ITB´s on an internally stock smallport with cams, and
I have more lower rpm torque than stock. So the real answer to your first question is... YES !! If you
fit ITB´s to a stock engine without other supporting modifications, you will lose power. They need to
be fitted in conjunction with an aftermarket ECU to work effectively. After that, you can add power
with cams and other modifications... head work, compression, exhaust etc.

Ah ST/BT stands for silver top / black top. It's great that you're getting more torque than original smallport. Is it because of the tune then? Did you ever thinking about adding VVT?

I'm also wondering if the my HKS ITBs + stock bigport internals are any good without cam modifications. I'm currently reading this website here: http://www.billzilla.org/4agmods.htm#115hp It's pretty interesting to read.

[aceforever]

OMGGGG IT CRANKS! OH MY GOODNESS!!!!!! WOO! Never have I been so happy for a car that doesn't start up.

(yes it was me being a total noob at manual cars and not holding down the clutch pedal when turning the key)

[jondee86]

Ah, I didn't know that the clock was constantly connected. That makes sense. I was looking into
this more and apparently, you're suppose to hook up the multimeter in series on the negative side
of the battery and check current.

Correct. If you are trying to track down parasitic loads that drain your battery over time,
you need to test to see what current is being drawn with the engine and all accessory items
switched OFF. The thing to be aware of is that most lower cost multimeters are only capable
of measuring very small currents (5-10A max). This means being careful to only test one
low current item at a time.

Cheers... jondee86

[jondee86]

Ah ST/BT stands for silver top / black top. It's great that you're getting more torque than original
smallport. Is it because of the tune then? Did you ever thinking about adding VVT?

,
There are a range of factors that influence how much torque the engine will make, and at what rpm.
Exhaust system, cams, cam timing, tune and a certain amount of luck VVT is not an available
add-on for the small port; not without installing a 20V head. There is no doubt that VVT does work
and helps the 20V engine make more midrange power. But I consider it to be an unnecessary
complication, when a properly built 16V can achieve the same performance without VVT.

I'm also wondering if the my HKS ITBs + stock bigport internals are any good without cam modifications.
I'm currently reading this website here: http://www.billzilla.org/4agmods.htm#115hp It's pretty
interesting to read.

At the moment I think that it is more important that you concentrate on getting your current
engine up and running, before you start making any further alterations. The reason being that there
have been countless projects abandoned because of over-complication with multiple modifications
being made simultaneously. You will learn more and have better success if you take measured steps
and complete each phase before moving on to the next.

Assuming that your engine is in reasonable mechanical condition, there is no reason why you should
not be able to get it running well. Once you have achieved that goal and have the satisfaction of
knowing that you have brought one AE86 back from the dead, you can consider modifications to
improve the performance.

The Billzilla pages are an excellent overview of what is possible with a 4AGE. Most of what is written
holds good, but there are areas that have been outdated by advances in technology since the time
of writing. As always, it pays to validate the facts by reference to more than one source.

Cheers... jondee86

[jondee86]

OMGGGG IT CRANKS! OH MY GOODNESS!!!!!! WOO!
Never have I been so happy for a car that doesn't start up.

MAN!!!! How happy are you going to be the first time that engine fills your garage with smoke

Cheers... jondee86

[aceforever]

I agree with your advice of not working on head internals at this point. I was merely thinking about what modifications I could make in the future to improve the performance. The stock cams are the least of my worries right now. The stock distributor, however, with limited trigger signal is something that I'm skeptical of. I have no experience in tuning engines or ECUs, but somehow 4+1 doesn't seem like it would give enough information for the ECU when normally people run 36-1 or 24+1. I'm going to continue with trying to calibrate the trigger settings on the ECU to read the RPM since now I've gotten the engine to crank. Oh, I should also do a compression test on all the cylinders.

That aside, is there any other writeups like Billzilla that you know of? I really like reading them and it helps me stay motivated.

---

Haha, sorry I got a little too excited there. With a massive project when I don't understand most of the things going on, I'll take all the little victories I can get

Also, curious about the aforementioned smoke, that should go away after running the engine for a while right? Is that just burning off the various old liquids in the combustion chamber?

[jondee86]

Here is some information copied from the Haltech manual for a later model ECU. It may help
to explain why the ECU can function with a 4+1 distributor.....

Haltech E11/E8 Instruction Manual
generate a voltage similar to figure E.5 on the positive wire. The amplitude of the signal will vary with the
speed at which the ferrous metal passes the pole piece. At low speeds the signal may only be several
hundred millivolts, but at high speeds it could rise to 20 volts or more. The sudden drop in the signal from
positive to negative seen in figure E.5 corresponds to the metal being directly in line with the sensor. As
can be seen, the signal is not a square wave required by the ECU, and at low speeds the signal amplitude
is too low.
The voltage input of the reluctor adapter must first go to a positive peak, which arms the circuit. When the
signal rises to approximately 70 - 80% of the peak value the reluctor adapter will generate a falling edge,
and when the signal crosses zero volts a rising edge triggers the Haltech ECU. If the wires are reversed
and the signal goes negative first, the Reluctor adapter will generate a pulse but it will NOT trigger the
ECU correctly resulting in incorrect ignition timing.

Standard Trigger
The simplest form of trigger pattern is what we refer to as Standard Trigger. With standard trigger, there is
a synchronising pulse that precedes each ignition event for the engine. For a 4-cylinder engine, the trigger
signal will have 4 pulses with each pulse occurring before the spark event. Typically, this angle will be 65°
to 70° BTDC. Ignition events typically occur at less than 45° BTDC.
The standard trigger pattern can be as simple as one pulse per ignition event on the trigger channel only,
but there are variations on this trigger that allows for varying degrees of engine synchronisation to allow
for more complex fuel and ignition outputs. The 3 variants of standard trigger are as follows:

Standard with No Home signal – This type of signal gives only a single pulse per ignition even on the
trigger channel. This type of trigger signal is suitable for running distributor ignition systems only. With this
information, the ECU only knows when a piston is approaching TDC. It does not know which piston, but
the distributor will distribute spark to the correct cylinder. The only possibility for injection mode is
multipoint injection where all injectors fire at the same time.

Standard with Home on the Crank – This type of signal uses a single pulse per ignition event on the
trigger channel, but supplements this information with a home pulse just before the pulse for cylinder 1
approaches TDC. Since the home signal comes from the crank, there is insufficient information for the
ECU to determine if the crank is at TDC compression, or TDC exhaust. As a result, the most complex
ignition mode that can be used is Wasted-Spark ignition mode where a spark always fires as a piston
approaches TDC of either stroke. The best fuel mode that can be used is “Semi-Sequential” injection
where half of the fuel pulse if fed to the cylinder on the correct cycle of the stroke (i.e. Just before or during
the intake stroke) and half the fuel is injected at the wrong half of the cycle (i.e. During the compression
stroke). Semi-sequential injection has the advantage that at least half of the fuel is injected on the correct
part of the cycle leading to better atomisation than with multipoint. In addition, the fuel is always injected in
the same positions for every cylinder, thus leading to smoother, more even running of the engine.

Standard with Home on the Cam – This type of signal gives a single pulse per ignition event on the trigger
channel, but supplements this information with a home pulse just before the pulse for cylinder 1 as it
approaches TDC of compression. With this information, the ECU knows exactly the position of each
piston and which part of the 4-stroke combustion cycle that it is on. With this information, direct-fire multi-
coil ignition is possible along with Sequential fuel injection.

Multi-Tooth Trigger
These triggers are typically found on Toyota, Honda and Mazda rotary engines.
The ECU is capable of triggering from multi-tooth pickups, as used on a number of production vehicles.
The ECU employs software signal conditioning to convert the multi-tooth trigger to standard form. This is
done by counting teeth from a “synchronisation event” (or Home signal), until a certain tooth is reached
which corresponds to the engine location specified as the Trigger Angle. The ECU then performs ignition
and possibly injection in the same fashion as the standard trigger.
After recognising the synchronisation event, the ECU will locate the first “standard” engine trigger by the
tooth indicated as Tooth Offset in the Ignition Set-up page. To find the remaining “standard” engine
triggers, the ECU counts a number of teeth equal to the total teeth in one CAM revolution, divided by the
number of cylinders.
For Example a 4-cylinder engine with a 24-tooth wheel on the cam and a corresponding home would have
the following setup values:
Trigger Angle: 65° (10° to 90° as required)
Trigger Type: Multi-tooth
Total Teeth: 24
Tooth Offset: 2 (1 to Total Teeth)
With these setup values, when the Home signal occurs the ECU will start counting the trigger teeth (24-
tooth wheel), when it reaches the tooth offset it will operate as a standard trigger. The position of the
remaining triggers is determined by taking the number of teeth in the trigger wheel (24) divided by the
number of cylinders (4). This number (6) is the number of teeth that is counted between triggers.
In this case the triggers will occur at the following teeth: 2,8,14,20. Each trigger occurs 65° (Trigger
Angle) BTDC of the current cylinder and will perform ignition based on this angle.

Cheers... jondee86

[jondee86]

Also, curious about the aforementioned smoke...

Yes... as I discovered when I fired up an engine that had been pre-lubed with a squirt of
engine oil in each cylinder... on first start the engine pumped an impressive amount of smoke
out the exhaust !!!!

Cheers... jondee86

[aceforever]

I understand how it's possible for a 4+1 trigger setup to work. I'm just wondering what the extra gears/signaling would provide to the ECU and what the advantages are.

Hahaha, I put in like at least 15ml of trans oil in each! How long did the smoking last for you?

[jondee86]

I put in like at least 15ml of trans oil in each! How long did the smoking last for you?

I suppose about 20 seconds. Because of the oil the plugs got fouled, and the engine
first lit up on one cylinder, and then slowly the other three joined in one at a time as
the engine picked up speed. Chug... chugged away like an old-fashioned steam engine
getting underway You probably won´t have this problem, as most of the oil will
find its way into the oil pan after you have been cranking the engine for a while.

More teeth on the trigger wheel improves timing accuracy. However, if the Haltech
generates a timing event for each tooth, this will be plenty accurate. With a 36-1 tooth
wheel for example, the ECU has to count teeth and create a timing event after 18 teeth.
Where the greater accuracy comes in is that if the rotational speed of the engine varies,
the 36 tooth wheel can detect the variation. And the higher number of teeth can be
useful when the ECU is required to created timed events at intervals other than 90 cam
degrees apart.

Cheers... jondee86

[aceforever]

Chug... chugged away like an old-fashioned steam engine
getting underway

Haha, man that would be a funny video to watch.

Where the greater accuracy comes in is that if the rotational speed of the engine varies,
the 36 tooth wheel can detect the variation. And the higher number of teeth can be
useful when the ECU is required to created timed events at intervals other than 90 cam
degrees apart.

Ah! since I only have fuel injection and spark timings, it's okay on that front. What does the ECU need to do when the rotational speed of the engine vary?

[aceforever]

Does this look like a healthy engine to you? I really want to clean this up but I'm forcing myself not to take everything off and clean it since I'm not sure if the engine will even run.

[jondee86]

Does this look like a healthy engine to you?

That looks more or less normal to me. A little bit of oil staining but not dark brown
or black as would be found in a neglected engine. The cams look very clean... they
usually get brown staining on the back of the cam (non-rubbing side). If there is any
sediment sitting in the pockets you can clean that out, otherwise it´s good.

You might like to check the shim to cam clearances while you are in there... all you
need is a set of feeler gauges. And the valve cover seals usually stay with the valve
covers, although you might find that there is a small dab of a silicone type sealant
holding them down in the corners where they wrap over the front cam seal cap.

Cheers... jondee86

[jondee86]

What does the ECU need to do when the rotational speed of the engine vary?

Probably shouldn´t have mentioned that, as it goes beyond anything that is needed
in your application.... but, since you ask The speed of the crankshaft increases on
each firing stroke, and by monitoring this change in speed it is possible to detect the
misfiring of a cylinder. This for example...

The Crankshaft Speed Fluctuation (CKF) Sensor is used by the PCM to monitor crankshaft
speed fluctuation. The diagnostic system is composed of a pulser rotor mounted on the crankshaft, and
a pulse pick-up sensor on the engine block. The PCM monitors the crankshaft speed fluctuations based
on the CKF signal and determines if an engine misfire has occurred if the crankshaft speed fluctuates
beyond a predetermined limit.

This kind of system is implemented on various modern vehicles, and will bring up a check
engine light if the fluctuations are above a certain level.

Cheers... jondee86

[aceforever]

That looks more or less normal to me. A little bit of oil staining but not dark brown
or black as would be found in a neglected engine. The cams look very clean... they
usually get brown staining on the back of the cam (non-rubbing side). If there is any
sediment sitting in the pockets you can clean that out, otherwise it´s good.

You might like to check the shim to cam clearances while you are in there... all you
need is a set of feeler gauges. And the valve cover seals usually stay with the valve
covers, although you might find that there is a small dab of a silicone type sealant
holding them down in the corners where they wrap over the front cam seal cap.

Whew, I thought it looked like some oil are burned into the head but I suppose that's normal.

Unfortunately, I already closed up the valve and sealed up the corners with the front cam seal. I'll keep the checking shim to cam clearances in mind next time I open it up.

[aceforever]

The CKF is pretty interesting. I don't think I'll really need that since you should be able to hear the misfiring right? And suppose I checked the timing every so often anyways it shouldn't be an issue?

[jondee86]

I don't think I'll really need that...

There are a lot of "shiny things" around to arouse the Jackdaw Instinct in the car enthusiast
Things that we feel we must have for their high-tech or race-inspired look... stepper gauges with
six selectable background colors, JDM badged oil filler caps, programmable shift lights, illuminated
push button for starting and more. These things are unnecessary and do nothing for performance,
but we are fascinated by them none the less.

I have "needed" a set of VDO gauges for years, but so far I have managed to get by with just the
OEM gauges. In reality I have found that when you are racing, there is seldom time for looking at
gauges. Your time is fully occupied in operating the pedals, shifting gears, steering and watching
out for other cars. When you are attuned to the sound, smell and feel of your car, you will know if
the engine is missing, overheating or starting to tighten up. But damn !!!... I still NEED that set
of fancy gauges with the built-in warning lights

Cheers... jondee86

[aceforever]

Haha, at some point I'll probably want work on things like that. But currently, I'm happy with the more pressing issues like getting the engine running

What style of VDO gauges did you get?

[jondee86]

What style of VDO gauges did you get?

I didn´t buy any yet, but the VISION range are the ones I like best. Part of the problem
is finding a location to mount them high enough that it is actually possible to view
them safely while driving. The traditional position in a single-DIN slot just above the
radio is too low... you just about have to park the car to read gauges down there.

If I mount gauges low they would have to have a warning light that flashes when the
reading gets to a dangerous level. At least that way you would be able to see the light
flashing out of the corner of your eye and be able to pull over and see what was wrong.
Maybe these marine gauges would do the job


Cheers... jondee86

[aceforever]

That's a nice looking gauge. I've seen some people replace one of the air vents near the dash, but seems a little tacky to me for street use. But it is high enough and good for racing applications.

Still haven't had time to actually test the trigger settings yet. I'm sick and only was able to buy the vacuum hoses I need for FPR, MAP and brake booster.

[jondee86]

That's a nice looking gauge.

I read a bit about that range (Viewline Onyx) and it seems that they need a master
control unit for programming... yada... yada... extra complication and more expense.
I don´t need that, so digging a little further I see that VDO actually have a range of
pressure and temperature sensors with an alarm switch built-in. And they also offer
a red flashing LED warning light, so I think I will stay with my first love Install the
gauges out of my direct line of sight, but mount the warning lights under the cowl
that sits above the factory instrument cluster. Simple and effective.

But that´s a finishing touch that I won´t be getting around to until I get the engine
running reliably again... and settle a few other items currently requiring attention.
Keep warm... drink plenty of fluids.... get some rest and you will be back in action
in garage soon enough

Cheers... jondee86

[aceforever]

I'm interested in seeing it when you're done

I'm also staying away from the garage until I feel better. I think I overworked myself with work and working on the car. But I'm very stoked on actually getting the engine started! It's going to be awesome!

[jondee86]

I'm interested in seeing it when you're done

Hahahahahah.... it´s taken me more than ten years to get to where I am now
with the car !!! And just when I get in sight of finishing this build phase, I strike
an intermittent loss of rpm signal on my ECU that I have to sort out before I can
get my new exhaust fitted.

So there is no saying exactly when I will get to the fitting gauges stage... but for
sure I will put a pic up when its done

Cheers... jondee86

[aceforever]

Hahahahahah.... it´s taken me more than ten years to get to where I am now
with the car !!! And just when I get in sight of finishing this build phase, I strike
an intermittent loss of rpm signal on my ECU that I have to sort out before I can
get my new exhaust fitted.

So there is no saying exactly when I will get to the fitting gauges stage... but for
sure I will put a pic up when its done

Cheers... jondee86

Any pictures so far?

[aceforever]

Been catching up on rest for the past few days, but this weekend I'm determined to get the engine idling!

Learned how to do compression testing. Wasn't so bad, just remove spark plugs and fit compression tester and crank. Cylinders 1-4 all are 179psi - 185psi. I read on old forums that 179psi is the original compression. So I'm not far off.


Will continue to get timing sorted out.

[aceforever]

Another update!

Spark plugs torqued to spec(18Nm), and connected up distributor and wiring.

Tidied up wiring by putting them into plastic conduits.


Also took video of cranking, tacho working and ECU picking up trigger data. It seems like the OEM tacho indicates 450RPM, however ECU is picking up 188RPM. Not sure which is correct.


https://www.youtube.com/watch?v=wC1boGd1AJY

[jondee86]

I'd say that 188 rpm was the more believable figure for cranking. And those
are good numbers for your compression.

These are a couple of pics of my engine after I fitted the filter plate. I would
have rather had a proper cold air box, but it was going to be too much work
to squeeze one in there, so I just took the easy route.




I have re-installed a few more bits since then, and tidied it up some. But you
can see the general arrangement of the ITB's.

Cheers... jondee86

[aceforever]

Omg, everything is so clean and tidy! After years of hard work I hope I can get my engine bay looking like that.
EDIT: I also noticed you were running some other form of ignition module. Pretty neat!

If 188rpm is correct, then something must be wrong with the OEM tacho signal. Is it because the OEM tacho is calculating based on the ignition firing, and perhaps that's not correct?

I'm going to unplug IGt wire coming from ECU to the Ign Module to see if it'll give me a reading closer to 188rpm to verify.

[jondee86]

Basically the factory tacho counts the number of times the coil
fires, and if you are using a single coil and distributor, it will be
receiving the correct input. Most likely there is some mechanical
slackness at very low rpm, and the reading will come right at
higher rpm's. Nothing to worry about, as the factory tacho is
just a simple gauge and does not interface with anything else.

Cheers... jondee86

[aceforever]

I disconnected the IGt from ECU and the tacho displays around 100-200rpm like what the ECU indicates. That prompted me to believe that the ECU has issues with the trigger settings on the ECU

I found a "Trigger diagnostic" option in the menu and it shows how many home and triggers the ECU counted. Trigger counts are all good (that explains why RPM is working, I think this is because of the filtering that the stock ignition module provides). However since I'm trying to get the home from the reluctor sensor, it might be trickier. I've played with the gain and filtering settings and it doesn't seem to help.

Another theory I have is that the home signal isn't being registered because of trigger angle and other settings due to trigger. I'll re-read the instructions on the manual there and check out older forum posts that you've linked.