Ref this thread:

https://www.thirdgen.org/techbb2/sho...hreadid=196934

I can now hard fault the problem when driving around city streets. Once the engine warms up the rough running and backfiring is happening between 2000-3000RPM all the time. I tested the coil and pick-up coil. No faults found. There still is no code. The car has great power and pull during the first 10 minutes of running. After that is all sluggish,sounds like crap, runs rough and of course the backfiring. I also did a fuel preassure diagnostic. No faults found. As I've mentioned theres no codes in the system and no SES light when the trouble is occuring.

Please someone have an idea on this.

Thanks again

 

Coolant temperature sensor needs to be replaced.

 

I was sort of suspecting that. Would that sensor not set up a code? And is it the ***** behind the alternator bracket?

 

No not as always. My 1989 GTA 350 TPI did not set a code. It only cost me $14 from Autozone and they usually carry it in stock. It's an easy fix.

 

No not as always. My 1989 GTA 350 TPI did not set a code. It only cost me $14 from Autozone and they usually carry it in stock. It's an easy fix. The sensor is seated on the Intake Manifold which in your case behind the alternator. It has a black and yellow wires I believe.

 

Thanks CC. Do you know if theres a resistance check that can be done on that sensor?

 

That I dont of. I was told that a scanner needs to be hooked up to the computer. But I am sure there is a resistance value but didnt have time to research it on this website. If you find out please let me know. Thanks.