1987 toyota levin converted to 20v, need help asap

johnoae86
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1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Mon Nov 21, 2016 7:12 am

hi there I bought a 1987 Levin a few months back the car had been previously converted
to the 20valve engine. Engine has been misbehaving since day one and I'm in need of some
guidance from somebody with more knowledge in this area.

At first the car would start and run drive etc but idled pretty badly and gave off a lot of
white smoke from the tail pipe. The car had also been lieng up in a shed for about a year
previous at this point. So shortly after I had changed oil and filter, genuine Toyota filter
along with mobil 1 10w60 motorsport oil, once driven smoke issue seemed to disappear.

So from there I moved on to replace the spark plugs. Upon removal one of the plugs,
cylinder one if I remember correctly...had the isolator part of the plug cracked in two
separate places. So initially I taught this was why my idle was really bad, I replaced all
four with denso iridiums and it improved the idle slightly but it still wasn't 100%.

Few weeks had passed and I started it one day as I do daily for a few minutes and the car
refused to turn off. I could remove the key from the ignition and the car would continue
to run> I had no idea what this issue was, but by cheer luck I replaced the battery with a
brand new bosch one and this somehow cured that issue. So for a further few weeks up
until last week the car was in its usual state running just not smoothly.

As of last week to begin with when I started the engine, it would jump incredibly high in
revs and after about 10seconds settle itself down slowly. Seems to be slowly but surly
idling worse as well. The car also started to leak water/coolant from the leak of pipe on
top of the radiator at a pretty quick rate, and as a few days passed the car gave up
starting, even with the aid of a booster. Its popping and banging and making all the
attempts to start, alarmingly seeing fire come from the trumpets when its attempting
to fire. I'm really lost with this as there's so many different issues.

I don't no were to look can anybody give me any checks I can do or any ideas as to what
is going on with this car it would be very appreciated.

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Re: 1987 toyota levin converted to 20v, need help asap

Postby jondee86 » Mon Nov 21, 2016 12:29 pm

I don't think you are going to hear any good news about this engine :(

1. White smoke from the tailpipe usually indicates that the engine is burning coolant.
Should have had a kind of sweet smell. Otherwise, it might just be steam.

2. Cracked insulator on a sparkplug can be the result of detonation (or pinging). That
can be caused by too much ignition timing.

3. Very high idle at startup is caused by the ISCV (Idle Speed Control Valve) being
gummed up with crud and sticking open.

4. Coolant getting pumped out of the radiator overflow together with hard/no start
is a pretty sure sign of a blown head gasket.

You will need to do some testing...
- compression test
- coolant test for presence of combustion products (does it smell like exhaust gas ?)
- check the cam belt is tensioned and cam timing is correct
- inspect plugs for signs of water after cranking
- check ignition timing if you can get the engine to run

But there is some good news... you can take the ISCV off and flush it out with carb
cleaner to remove the crud, and it should work fine again.

Cheers... jondee86
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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Mon Nov 21, 2016 1:58 pm

my white smoke issue was eliminated after oil and filter change it was only really on idle once drove for even a minute down the road smoke would disappear and stay gone, I cant see any leaks around head or water pump, engine was rebuilt a little over a year ago before the car was stored in a shed, and it got a lot of work including new timing belt and water pump, cam pullys etc.. head was also off not shure if gasket was done, I will try do compression test and clean iscv out, when I pulled plugs all I'm getting is a slight bit of fuel on the end of the plug

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Re: 1987 toyota levin converted to 20v, need help asap

Postby oldae82 » Mon Nov 21, 2016 4:14 pm

You have so many different symptoms that it can be difficult to isolate individual causes. It would be hard to dismiss jondee's assumption of a blown head gasket with out proof otherwise. Best bet is to get your base lines- compression within parameters, timing correct, no flooding (trumpets means carbs, right?) no fuel in coolant or coolant in oil, and then if you can get it to run check for spark leaks- cracked dist. cap, arcing wires (run it at night and see if you get a light show), and then vacuum leaks- spray wd-40 or some such on gaskets where air might be getting in. Also, a bad ground in a critical location can cause all sorts of weirdness.

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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Tue Nov 22, 2016 5:48 am

I'm going to start with some of the tests stated above, my engine has no distributor so I cant manually adjust ignition timing, my ecu is a gotech pro x I've been led to believe ignition timing is controlled by this ecu so would need to plug into the car somehow to adjust it, I have no equipment to plug in to that ecu and not sure what I would need, I cant see any other diagnostic port for flash codes, the vast majority of the wiring was wire tucked and everything's runs back to the ecu and a separate relay board in the glove compartment, in terms of vacuum leaks I reckon I have one, when brake pedal is applied at idle my idle raises slightly then drops when I take my foot of the pedal, used carb cleaner on all hoses and didn't find much but on visual inspection, I found a hose cracked badlyat either end it was routing from rocker cover back over near injectors, hose only about 4/5 inches in length, unfortunately I cant check and see if changing that pipe helped in any way as the car is not starting

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Re: 1987 toyota levin converted to 20v, need help asap

Postby jondee86 » Tue Nov 22, 2016 11:19 pm

A picture of the engine would help ;) If you don't have a distributor, your ECU is
most likely running a wasted spark setup with external coils. And you are correct,
the ECU will have full control of the ignition timing. That being the case, it is
unlikely that it will have changed since the car was first tuned.

Judging by the comment on the Gotech website, you would need access to a laptop
with a serial port and running XP. Then you could download the tuning software and
check to see what the ignition map looks like. Not something I would bother with
at this stage... not until you have eliminated all other possibilities.

The short hose you refer to is most likely the hose from the PCV to the vacuum rail.
Some leakage there would tend to raise the idle, but not to the 4000rpm or so that
you can get with an ISCV stuck open. The ECU may have a setting to raise the idle
when an electrical load is switched on (for example, brake lights, head lights or
blower for the heater), so I would not be too concerned about a small change in
the idle speed.

Since you have an aftermarket ECU, the engine is most likely running a MAP sensor.
Do you see a small rubber hose running from a tapping near the throttles over to
a black cube with an electrical plug mounted somewhere on the firewall ?

Cheers... jondee86
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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Wed Nov 23, 2016 6:15 am

I cant seem to post the photos on the engine bay on here... have had a look and cant seem to see a black cube with electrical plug mounted on the firewall, could you send me a photo of what this looks like, I have noticed so far about two sensors both on either side of the engine that have nothing plugged into them also, in general there are very few electrical connectors to be seen around the engine bay

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Re: 1987 toyota levin converted to 20v, need help asap

Postby jondee86 » Wed Nov 23, 2016 11:52 am

This is a "Blacltop" 20V conversion. You may have a "Silvertop" version (refers to
the factory colour of the cam covers). The differnces between the two engines don't
matter once you are running an aftermarket ECU...

Image

In this pic the MAP sensor is at the top left, mounted on the firewall. However, it
may be mounted alsewhere if a longer rubber hose is used. The MAP sensor is used
as the primary load sensor for the ECU, and the engine will not be happy if the hose
has become disconnected.

Cheers... jondee86

PS: Ignore the red arrow... it was already on the pic :)

PPS: To post pics you need to upload them to an image hosting site (photobucket etc)
and then link them using the [IMG] tags.
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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Wed Nov 23, 2016 2:51 pm

Had iscv off today and cleaned each individualy, a big build up of black sutt badicky used carb cleaner got them good and clean, will find map sensor tommorow and inspect, I also noticed the butterfly valves are not completely closed if I tension the throttle cable by hand the close fully the gap is very minimal on each valve but would this be ok to have that small clearance allowing air in ??

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Re: 1987 toyota levin converted to 20v, need help asap

Postby jondee86 » Wed Nov 23, 2016 8:15 pm

You should have one of these (ISCV) underneath the throttlebody nearest to
the firewall...

Image

If you do have one the throttles should close all the way. If you don't have one,
then the throttles may have been set to be a tiny bit open to let idle air into the
engine. Normally, in the factory setup, the ISCV lets ALL the idle air into the engine.

Cheers... jondee86
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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Thu Nov 24, 2016 3:17 am

Will search for map sensor and this iscv sensor today when I get time to get down to the garage and keep you updated

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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Thu Nov 24, 2016 7:05 am

OK so I've just been out in the garage for a while and cannot seem to see anything like a map sensor or iscv sensor atal atal, what I have noticed is a rubber hose capped around the area near the firewall that you said the map sensor would be located and underneath throttle bodies slightly away from the firewall is a connector for some sort of sensor to be plugged into which I'm guessing was the iscv once upon a time, why would hose for map sensor be capped if I am looking at the right hose... Is it possible that the aftermarket ecu is in control everything without aid of some sensors, its a very unusual set up

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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Thu Nov 24, 2016 7:07 am

Image

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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Thu Nov 24, 2016 7:10 am

Image

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Re: 1987 toyota levin converted to 20v, need help asap

Postby jondee86 » Thu Nov 24, 2016 12:33 pm

johnoae86 wrote:Is it possible that the aftermarket ecu is in control everything without aid of some
sensors, its a very unusual set up

Looking at your pics it is very likely that the ECU is using the TPS (Throttle Position
Sensor) as the load reference. This means that a MAP sensor is not required.

For the engine to get a position reference there will usually be a crank angle sensor
and a cam sensor, and these are commonly found in the base of the distributor found
on the back of the exhaust side cam. That is, the distributor cap, wire and rotor are
removed, and the base fitted with a blanking plate or cover. If you don't have that,
I would expect to see a toothed wheel with a sensor attached to the crankshaft pulley
at the front of the engine.

There is also a vent connection (about 12mm dia) on the back of the intake side cam
cover. This may be left open or fitted with a small filter.

What is the ignition setup ? Do you have two coilpacks with two wires from each, or
four coils with one wire from each.... or something else :D

Cheers... jondee86
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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Thu Nov 24, 2016 1:25 pm

OK so bit of a break through I managed to get it to fire up tonight after a lot of cranking and after fiddling around a little I think I have an injector issue possibly hense the no start issue, when I got it to fire the car ran slowly and built itself up and sounded like it was missing, I started at cylinder 1 pulled injector connecter off and its like it idled better, cylinder 2 connecter off it hesitated a lot and stutter, same behavior on cylinder 3, and finally in cylinder 4 with connecter off there was no change what so ever on how the engine ran, I found a blanking plate in the area you mentioned but also have at toothed wheel out the front with a pick up sensor, ignition set up car is running four leads to one coil.

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Re: 1987 toyota levin converted to 20v, need help asap

Postby jondee86 » Thu Nov 24, 2016 2:39 pm

If there is just a blanking plate (no distributor base with sensors inside) then the
ECU will be running off the toothed wheel. This is one of the "modes" available with
the GoTech Pro-X ECU. The likely connections are as shown here...

Image

If you have a single 4-pole coil it is almost certainly operating in wasted spark with
two ignition and one power input i.e. plugs firing together in pairs. The injectors will
also be wired in pairs with two injectors firing at the same time. This is the best
that the ECU can do without a cam sensor.

So look into the possibility of a fuel supply or injector problem. Maybe get the
injectors cleaned and flow tested, and check that the pump is delivering adequate
flow/pressure to the rail. That is a more likely cause when the performance drops
off over a period, rather than the ECU failing. Also check that you don't have any
injector wiring rubbing on a sharp edge anywhere between the ECU and the injectors.

Cheers... jondee86
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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Sat Nov 26, 2016 5:50 am

When I disconnect injector four there is no change in engine, I have current coming through the wire to the sensor, this is surely faulty injector causing my hard to start problem and bad idle

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Re: 1987 toyota levin converted to 20v, need help asap

Postby jondee86 » Sat Nov 26, 2016 11:41 am

See if there is an injection specialist around your location and check if they
have a clean and test facility. If not, you might have to send them to an out
of town injector cleaning and flow testing specialist.

But before you do that swap the #3 and #4 injectors around and see if the
"dead" injector changes places.

Cheers... jondee86
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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Sun Nov 27, 2016 7:30 am

Could this one injector be causing a no start issue, when I tried to start today I had no joy only huge backfire, I taught that at least with the other three injectors doing there job it would be enough to run but run badly as it did yesterday when it was running and was extremely down in power

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Re: 1987 toyota levin converted to 20v, need help asap

Postby jondee86 » Sun Nov 27, 2016 2:22 pm

Reality check time :)

A cylinder can be dead if it has no fuel or no spark. Have you pulled all the plugs
and cleaned/dried them ? After a lot of cranking there can be enough fuel in the
cylinder to wet the plug and keep it wet for some time. Longer if the plug is black
and sooty. If you pulled them all... what did they look like (pic ?).

Pull the plugs and leave them out overnight to let the fuel in the cylinders
evaporate. Brush soot off the plugs, clean them with carb cleaner or similar,
and then dry them with a propane torch or electric hot air blower. Engines always
start better with a set of clean, dry plugs :)

For the engine to run it needs air, fuel and spark. And the spark has to happen
at the correct time. Normally, an otherwise healthy engine will run on only two
cylinders, so yours should run on three.

Easiest way to get an idea of the engines condition is to do a compression test.
Provided you have a fully charged battery, it only takes a few minutes. If you
don't have a tester, try any of your friends who mess with cars and see if they
can help you out.

Since the engine did run (kind of) you probably have air, fuel and spark. But one
of them is out of whack. Pays to check the obvious things... plug leads connected
to the correct cylinders, trigger wheel pickup not loose and correctly adjusted.
The pickup needs to be as close as possible to the teeth without actually touching
them... 0.50 mm should work.

Cheers... jondee86
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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Tue Nov 29, 2016 8:37 am

OK update so far, taking into consideration what you said about the compression test I went ahead and did it last night, firstly though I had plugs out on a few ocssions overnight cleaned sutt off them but wasn't getting the car to start, sometimes o would other times I wouldn't, so compression test results cylinder 1 200psi cylinder 2 195psi cylinder 3 195psi cylinder 4 180psi (cylinder four were I suspect a faulty injector) I've been told by a mechanic that would eliminate any big issues with the engine and would be a good compression test what do you guys think ??

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Re: 1987 toyota levin converted to 20v, need help asap

Postby jondee86 » Tue Nov 29, 2016 1:09 pm

Revisiting your original post in the light of the further information you have provided.

johnoae86 wrote:Few weeks had passed and I started it one day as I do daily for a few minutes and the car
refused to turn off. I could remove the key from the ignition and the car would continue
to run

If all/most of the OEM underhood electrics have been removed, it is likely that one of
the relays in the glovebox is controlling power supply to the ignition and ECU. This one
sounds like you have a relay that stuck closed and did not release when you turned the
key off. Or it could be that your ignition switch has a problem.

I replaced the battery with a brand new bosch one and this somehow cured that issue.

A bit of extra voltage might have been enough ?

As of last week to begin with when I started the engine, it would jump incredibly high in
revs and after about 10seconds settle itself down slowly.

Only extra air can push the idle up real high, so probably crud was causing the throttles
to stick partially open. Vibration from the running engine would cause them to settle
back to the nearly closed position for normal idle. Cleaning them should have fixed this.

Seems to be slowly but surly idling worse as well.

Engines are not organic... they don't heal themselves when there is a problem :)

The car also started to leak water/coolant from the leak of pipe on top of the radiator
at a pretty quick rate,

Coolant getting pushed out of the overflow and/or bubbling and foaming in the expansion
tank is a solid pointer to a head gasket leak between the cylinder and water jacket. You
will need to investigate this further when the engine is running again.

Its popping and banging and making all the attempts to start, alarmingly seeing fire come
from the trumpets when its attempting to fire.

Either an ignition problem, timing problem or maybe a fuel supply problem ?

Your compression test shows #4 as being low compared to the other cylinders. And
this is the "dead" injector cylinder. A small head gasket leak can let gas out of the
cylinder and also let coolant into the cylinder. This will need further investigation.

Bad running or not running could be down to low voltage in the ignition circuit. You
need to try and figure out what the relays do, and check their condition. Take the
relays out and measure the contact resistance. If a relay has been carrying more than
its rated current the contacts may be bad. Contact resistance should be essentially
zero, so replace any that have high resistance or show signs of overheating.

If the fuel pump runs when you turn the key ON, try running the return line from the
fuel pressure regulator into a bottle to check the flow. Gasoline should squirt out
in a solid jet with a fair amount of pressure. Keep a fire extinguisher handy and
get someone else to turn the key. Low flow or gas that just dribbles out indicates
a blocked filter or some other obstruction.

The more tests you do, the more you narrow down the possible causes... the answer
is out there somewhere :)

Cheers... jondee86
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Re: 1987 toyota levin converted to 20v, need help asap

Postby johnoae86 » Tue Nov 29, 2016 3:29 pm

Will keep digging and update when I find a break through

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Re: 1987 toyota levin converted to 20v, need help asap

Postby oldae82 » Mon Dec 05, 2016 6:48 pm

I'm not nearly as knowledgeable as jondee in the specifics he's citing, but I do know from what work I've done that you can't skip steps and make assumptions. You have to know that a certain system is working correctly before you can move to the next system. If you don't know, then you've left an enemy behind you, and it'll jump up and bite your butt.

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