[mgarblik]

Does the engine run the same, (bog), no matter what the temperature is? Trying to figure out if closed/open look has anything to do with the bog. Basically cold, open loop, fuel delivery is primarily determined by MAF, temperature of water and air and throttle position. Once in closed loop, (warm), the front O2 sensors become the primary inputs for fuel delivery, but the other sensors are still used for fuel trim. If it runs the same cold and hot, (open and closed loop), again the MAF comes into question. You will get it!

[firechicken]

Originally Posted by mgarblik

Does the engine run the same, (bog), no matter what the temperature is? Trying to figure out if closed/open look has anything to do with the bog. Basically cold, open loop, fuel delivery is primarily determined by MAF, temperature of water and air and throttle position. Once in closed loop, (warm), the front O2 sensors become the primary inputs for fuel delivery, but the other sensors are still used for fuel trim. If it runs the same cold and hot, (open and closed loop), again the MAF comes into question. You will get it!

Good question. I can try to test that this morning while the engine is cold. It comes up to temp very quickly and goes closed loop. It has a low volume cooling system apparently for that purpose and it's warm summer temps here now.

[KS circutguy]

I may run out to the pick n pull today and see if I can find a maf. I found a list of cars that use the same one so might be a quick way to test this.

Make sure these ECU parts are OEM type not aftermarket junk.
If you start putting unknown manufactured parts on, especially computer controlled components it'll lead you down the wrong path.
Only change 1 at a time to confirm or not the parts effect on the problem.
It could also be wiring or connector related.
I'd grab those at the bone yard if available, new ones are pretty costly and rare to find new OEM.
Also grab a factory manual for the vehicle on Ebay.
Good luck.