code 33 and irratic idle when cold

[whitey]

I have a 1986 coupe which I recently purchased. When I purchased the car it had code 33 and code 36. replaced both MAF relays and also replaced IAC and TPS and properly adjusted TPS to .62volts. Cleared the codes by disconnecting battery and started car and I still have the same problem only now I just have code 33. When I start car up it idles good for 30 seconds or so and then starts running real rich and will lots of times die. If I accelerate the car it runs fine and if I let it get warm it will then idle perfectly at about 600RPMS and doesn't run rich. I took mass airflow off and cleaned all the connection and the inside of the mass airflow with no residue contact cleaner and this did not help. No drive ability problems drive car one block and it will idle perfect the rest of the time.

 

[vader86]

Dead MAF sensor.

 

[HPG]

Was one of the relays you replaced, the burn off relay. When I replaced the MAF power and burn off relay, my problem went away. No codes. Look at this, it may help. http://www.c4vettes.com/ecm.htm

 

[omega1940]

I have replaced BOTH relays (power and burn-off). Most recently on Monday or Tuesday of this week. These relays are just behind the battery on the firewall.

 

[omega1940]

In my post I mentioned that I had replaced the MAF with a new, nearly $400 high-performance MAF from Mid-America. It is adjustable. I have probably changed the adjustment for airflow about 30 times in the past month trying to find a perfect spot to elimiate the problem. It doesn't stop the problem. I've returned to the old MAF, which was working fine, and as I said in my post as well, it works for a few days then starts acting up again.

 

[omega1940]

Whitey, my acts the same way. As long as the car is under power, pushing on the accelerator eliminates the problem. The minute I reach a stop light and have to stop, it nearly dies unless I keep reving the engine. Am I right that you haven't solved the problem either. The only thing I can think of doing now is returning the adjustible (and expensive) MAF to Mid-America and get a new Bosch MAF. It could be that both my old MAF and the new one are both bad.