I have a 86 IROC Z28, Stock Engine When I turn the key on the check engine soon light goes on, then goes off. My mechanic tells me he can't pull codes because it doesn't stay on long enough.
The car is running in open loop full rich mode. O2 sensor is working fine. When he was able to pull a code he got a 51. So we replaced the Prom, but it didn't fix the problem. The car was running too rich and MELTED the cat. I have also replaced the
spark plugs and wires. In fact the manifold got so hot it melted my new wires, so I had to buy a second set. The car had been running rough and I could smell unburned fuel. Anybody got any Ideas?

 

1) fire your mechanic
2) try another ecm, and a new o2 sensor.
3) Download some scan software and build a cable. Send is a log of it running idle on start up, and a small log well after the fans have come on at least twice.

-- Joe

 

Thanks Joe,
1. I fired my boyfriend
2. Ordered a new ECM
3. Bought a new O2 sensor
Where can I download that scan software?
Thanks again

 

:yourock:

 

haha. Normally the only way I break up relationships is by dragging the guy outta the house in handcuffs!

Setmestr8,

www.moates.net has all the info on getting/building the cable, and link to free software. Good luck

-- Joe

 

Uhh, correct me if im wrong some one, but if you are in open loop all the time, then how can you tell the 02 sensor is working fine? In open loop, all commands are ignored given to the ecm by the o2 sensor.

 

You'll still see O2 crosscounts on the scanner.

She needs to send us a log so we can tell whats going on.

-- Joe