Can't figure this out for the life of me.

[wannagte]

I have searched and found some threads similar, but not the kind of info I was looking for.

Ok, this is my first post on this forum, I'm not new to the supra I've own several over the last 8 years, but this is my first 7mgte.

I bought this mk3 with no oil pressure, replaced the motor. engines starts first try (omfg that has never happend to me). let it idle and warm up for about 15 minutes, it ran great, then went for my test drive. on test drive I stop at a red light, light goes green, I stall the engine. I start it back up and tromped on the gas, half way through the intersection car starts jerking, managed to get it off to the side of the road and do a quick check...... nothing looks wrong. so I checked the codes and code 21 and 34 come up. call up a friend for advice and he said to check all of my IC ducts. BINGO! the pipe that comes right off the turbo blew off. Ok, so I fixed it and reset the ecu. now the only code is 21 (oxygen sensor) but the same problem.

Here's whats going on, I start and it'll lope once or twice then stall. I can rev it all the way to red line, but I have to feather the gas to keep it running or it stalls. I have replaced the t.p.s. checked every vaccum hose at least 4 times, I have done the same with IC piping and I retorqued the intake manifold. I did manage to drive the thing and it got really good boost. I have an adjustable fuel pressure regulator with a pressure gauge on it. the fuel pressure lopes before the engine does, but picks back up. I've been scratching my head for a week now and can't figure this out.every night after work I try something new. If any of you guys can help or have ideas please feel free to let me know.

oh, the 7m has a ct26 with 57 trim, aftermarket pistons (can't think of the brand right now), cometic metal hg 86mm bore and the fuel pressure regulator, but other than that stock.

*edit: the egr is also blocked off, the engine with no oil pressure was jdm. so I copied it over to the new engine.

 

[TuRbOdReAmZ87]

Check the spark plug wires and plugs themself. Could be an issue.

 

[Quin]

If you're going to run no EGR, make sure you use the JDM ECU as you may run lean at part throttle mid to high rpm driving.

Have you checked the timing?

EDIT: Btw, excellent first post. Easy to read with a lot of information for us to help you Welcome to SM!

 

[Poodles]

Sounds like you still have a boost leak...

 

[supraguy@aol]

Sounds like you still have a boost leak...

I agree. When you rev it up, do you hear a whistling/whining sound from the turbo? If a hose is semi-popped or popped off, the turbo tends to spin a bit faster.

 

[wannagte]

the plugs are brand new (iridium), put them in while i had the engine apart.

I really don\t think I have a boost leak, although that's how it's acting. I do not hear any hissing nor have i felt any boost/vaccum leak, checked. and when I managed to drive it the boost gauge almost went up to 4 (stock gauge), but I guess I can check them again.

I would time it if I could, but it won't stay running. I have moved the ignition timing around and not much difference. I'll check and make sure everything is at tdc tonight.

I'd almost say fuel but last time I had a fuel problem I could'nt rev my 5m past 1500rpm.

Keep it coming! thanks for you help.

 

[IwantMKIII]

Your FP should NOT die down with the engine. It is a separate system in a way and should for the most part stay constant at idle. Only way for FP to significantly drop in sync with the engine would be something electrical. At least that's all i could think of

Code 21 will not affect driveability of the car.

i still would suspect boost/vac leak. You need to perform a boost leak check.

 

[ForcedTorque]

. I have an adjustable fuel pressure regulator with a pressure gauge on it. the fuel pressure lopes before the engine does, but picks back up.

Sounds as if you could have a dying fuel pump to me. As IwantMKIII stated, your pressure should not go out with the motor. Your gauge should show pressure for several minutes even after you turn the car off. It could also be a problem in your wiring going to the fuel pump. You may want to consider doing the 12V mod to your pump. It's very easy, and very cheap. Check the tech section for a thread I did with pictures on how to do it. It can be done for $20 or so. If your pump is still stock, you may want to consider the Walbro pump as well. I did both the pump and 12V mod with no knowledge of any electrical, and no experience in pulling a pump.

Also, there is a thread somewhere in the tech section that shows a very cheap boost leak detector you can build with under $10 at your local Lowes home Depot. I have links to both of those threads in my build thread, but that thread is over 100 pages, and finding links from the past is difficult even for me.

The first two things you should do though, are to fix the code 21, and search for the reasons blocking off the EGR are bad. But again, if you are running the JDM ECU, you may be OK.

 

[edward_mccleary]

i kinda had the same problem i had brand new bosch plugs and as soon as i changed them it fixed the problem.

 

[wannagte]

I'm gonna take the night off tonight. I think I'm just running around with my head cut off.

tomorow night I'm going to make sure everything is at tdc, make sure (again) that all my IC pipes and vacuum hoses are on gudanfuggentite, check my plugs (who knows, I'm not going to throw any of your guys suggestions to waste) and check out that 12v conversion for the fuel pump.

 

[Poodles]

Ditch the iridiums and get NGK or Denso coppers or platinums.

Iridiums need to be gapped like any other plug, but they tell you not to because they're easy to damage. They're a fad that needs to die...

 

[IwantMKIII]

^comon now poodles, ditch the platinums and stick with coppers on a turbo car. And don't forget to go one heat level cooler.


BTW, if your FP is on its way out, doing the 12V mod will most likely finish the job so be prepared.

 

[Poodles]

I like platinums better because I'm not pushing huge numbers, and I'm lazy and don't like changing my plugs all the time.

 

[IwantMKIII]

^never had issues, i ran my last set of coppers 7K miles and they were fine, only reason i changed them was b/c of the fire.

 

[wannagte]

ok, problem fixed. 12v mod for fuel pump was the remedy. but instead of using the relay and all that, I bypassed the stock relay thingy with the jumper wire. but now i have excessive fuel consumption and I mean excssive. gonna do my timing later, maybe that'll fix it. If not I'm going to have to reduce the pressure in the fuel rail.


Thanks again guys. the info was very helpfull.

 

[Poodles]

That's not a smart mod, if you look up WHY there is a relay you'll understand.

It's a band-aid in your case, and it's only covering up other issues...