89 supra turbo missing after warm

[Rob1]

I recently bought a 1989 supra turbo, targa, 5-speed. it has an 87 front clip due to a wreck by the previous owner, it has a T61 turbo, 550cc RC injectors, a SAFC11, and i have recipts showing that at some point it was tuned by a local speed shop, Carma performance engineering. I talked to Carma the remembered the car because they said it had huge issues with the engine wire harness. they replaced it but its still not perfect. they said when it left their shop it was running fine. ok now up tomy ownership of the car. when starting in the morning, it take maybe ten rotations of the motor befor it hits a lick, then dies, about 5 rotations after that it will start and if givin a little gas it will run fine. it runs perfect untill the idle dropps when the thermostat opens, at that point it starts missing pretty bad at idle, somewhat during steady cruising, but non at all durnig hard acceleration. It will also die when clutch is pressed only after moderatly hard acceleration. I have no clue what it is. The check engine light is on and throwing codes 21-o2 sensor signal, 22- water temp sensor signal, and 52-Knock sensor signal. any ideas about what im looking at here? Thanks to all who read that whole thing!! any advise is welcomed

[jtown125]

I think tennessee puts a curse on supra lover's. lol

On warmup I can understand missing.
But after its warm there is a problem.


I have absolutely no idea what the water temp sensor would have to do with it,
but mine doesn't read right anyway...
And im just guessing that the knock sensor picks up due to the upgraded turbo and boost... and especially if its missing...
but it could be much worse than that.
im just as confused as you are on the fact that it doesn't miss at the higher rpm's.

I would start with the o2 sensor, i have had problems with other cars I have had that are similar to the problem that you are having.

[cre]

Break you post up into paragraphs please. It makes it easier to sort through.

First. The code 52 is a critical code. If that's present the ECU will DUMP a lot of extra fuel in and pull a lot of timing advance. You need to take care of that FIRST. Do a search on the forum for knock sensor rewire and make sure they're both actually present and connected (there are two sensors on the GTE block, only one on a N/A).

The next codes to look at are the coolant temp and the O2.

The stalling, crap drive-ability and difficult starting cannot be looked into any further until at least the coolant and knock codes are fixed; The knock code is the worst of them all.

[Rob1]

Thanks, the knock sensor code is because the knock sensor on the driver side of the car under intake manifold is broken off.

i have not yet located the second but there is a way to bypass the knock sensor to kill that code right? are those instructions in this forum?

[Rob1]

and could the ecu's adjustment to the knock sensor code be causing the o2 sensor code because the car is running very rich?

[cre]

Originally Posted by Rob1

Thanks, the knock sensor code is because the knock sensor on the driver side of the car under intake manifold is broken off.

i have not yet located the second but there is a way to bypass the knock sensor to kill that code right? are those instructions in this forum?

On the GTE block the #1 knock sensor is located between cylinders #1 and #2. The #2 knock sensor is between #5 and #6. On the GE there is only one located between #3 and #4.

No, you can't bypass it... not without a lot of creative electronics (see custom).

Originally Posted by Rob1

and could the ecu's adjustment to the knock sensor code be causing the o2 sensor code because the car is running very rich?

It's more likely that the ECU running in limp mode (that's what you're experiencing by the way) has killed the O2 sensor. The O2 sensor is the least of your worries. I'd just unplug it for the time being.