1JZ problems

[urantia]

excellent thanx!
rep for ya.

[cressida_1jz]

The car is now running rich all the time.When you step on it,it coughs and splatteres black smoke realy bad.Then starts to run on 1 or 2 cylinders and blows white smoke.Smells like un burnt fuel.1/2 a tank for 30 km

[Cressida91GLX]

wow what a fuel economy! get your ignition system checked out by the professional or be a good man and replace everything ( ignition system plugs, coils) that will give you a trouble free engine for a long time.

Also is your ECU giving you any code. And try these remidies
http://www.thermactor.com/forum/viewtopic.php?t=9213

[chris davey]

yeah, check for codes first.

How do you know it is running on 1 or 2 cylinders? Does it do it at idle?

If so, pull each coil pack lead off until you find ones that the engine note doesn't change when you pull it off. If it truly is running on 2 cylinders 4 of them will not change the engine note. Then you know which cylinder is the issue.

Do a compression test just to be safe.

You need air, fuel and spark to run. Unless there is something seriously wrong in the head you should have air. Next check injector plugs to make sure they are firing. You can take these off just like the coil plugs and see if it changes. Have injectors ever been cleaned?

Then ignition, pull plugs and see what they look like, (search google for reading spark plugs), then check all coil packs (there is some stuff you can put on them if they are cracked and tape them up) or get new ones, then check the coil plug connecters look ok. Then I supose next is the igniter but if that wasn't working then I don't think it would start at all.

That is all I can think of.

Good luck

[cressida_1jz]

I pulled the plugs out again and they were all BLACK ecept no 2

I put another set in BKR6E.Found coil 4 was arcing out.So i taped it up and stopped that.

Got the guy that wired up the car and tested the MAP sensor,TPS,coolant temp and air intake temp sensor and they tested up fine.

Air fuel ratio guage is always reading rich.o2 sensor could be stuffed.

Its not always doing it though

After we finished doing all that,we took it for a drive and it went well.Still got plenty power.

I left the car at work untill its fixed.

Il give it to the mechanic next door to give it a compression test on Monday to be on the safe side.

What pressure should the cylinders be at?

[chris davey]

As long as they are all similar it should be fine.

My engines have ranged between 155 (on all 6) and 180 (on all 6).

So it is driving ok now then? Try what I said above and tell us your results.

[cressida_1jz]

Its still got heaps of power but dont want do drive it if im gonna get stranded.

When it used to play up,Cylinder 3,5,6 were dead

Didnt play up all day on Saturday after we swapped the coil that was cracked.

Il take it for a run on Monday and see how it goes.

Il do them things u told me to do.

Cheers,Mark

[TTMX83]

Brad(umpagrande) on the toyotacressida forum has got the same problem with his 1jz. He was also trying to diagnose it and found one coil short on cylinder 3 I guess. Might be the same problem and might help talking to him.

Yep, that's me. Exactly the same problem but mine is getting worse now, at the moment it is doing it all the time. I have found that it's not the spark plugs, coils or igniter. All those have been replaced or at least tried with other, known to be working, parts. Next to test is the injectors as I think a couple of them could be stuck open, or the ECU is giving a constant 12 volts to a couple of the injectors. For the full run down of what I have done to date, click here: http://thermactor.com/forum/viewtopic.php?t=9213

I have no experience in this part of the car, I can only check simple things like no open curcuit in the loom, or finding a short. Any ideas would be greatly appreciated.

Cheers Brad.

[cressida_1jz]

I think myself its fuel related.Maybe injectors stuck open aswell.

Like i mensioned earlier,cylinder 2 spark plug wasn't black

But i wont know until i pull the injectors out and get them flow tested.

Such a **** of a job.

[TTMX83]

Yeah 3 & 5 spark plugs on mine are very wet. Those 2 injectors are on the same curcuit in the wiring diagram so that helps. Mine is doing it all the time now....

Yes it is a prick of a job. I'm going to change the injectors around first and see if the problem follows those injectors.

Brad.

[TTMX83]

Mark: How is the car running today? Mine is still no good, really starting to run out of ideas on what it could be.

[Cressida91GLX]

replace it with my car you will get a reliable 7mge with just a single problem to fix.

[cressida_1jz]

My AFR guage was always showing rich on Saturday so i ended up giving the car to the EFI guy 2day.He put it on the scan and found the oxy sensor was rooted.I drove the car on Saturday with it disconected and it went well.

He put another 1 in and it was going fine.Found the no.4 coil was fucked aswell.

I ordered 6 new ones today and 6 new coil plugs.Should have them next week.Sick of trying to find good 2nd hand ones.

.

[urantia]

what are you paying for a full set of coils?

[cressida_1jz]

There Nippon Denso ones imported from Japan.

He didnt give me an exact price but said about $80 each last time he got them for a Soarer.