Finally got my car on the road for the first time a couple weeks ago. She runs great but occasionally throws an SES light and goes into limp mode - fan on full time, no torque converter lockup, poor throttle response. When I jump pins 5+6 on the ALDL it does not give a flash code. If I leave the car off for a few minutes, the problem goes away and I can get the standard 12 flash by jumping the pins but no other codes, then the car will run fine again. Any suggestions for troubleshooting this or figuring out the code? I've read that a bad sensor will trip a light but shouldn't put the car into limp mode. Is this a sign of a bad ECM?

Funny side effect, don't know if this helps or not, but running normally she burns some oil when I apply throttle from idle or near-idle - even a gentle roll out will leave a small cloud of blue smoke. BUT when the SES light is on, I can mash the pedal to the floor without seeing any smoke behind me. Any ideas about this?

Engine is a bone-stock '87 LB9 with AIR delete, been sitting for who knows how long (didn't run when I bought it a year and a half ago). New plugs, wires, coil, and ignition module.

 

im having a similar problem. have u figured anything out?

 

Yes, the ECM was damaged. I found a similar one in a junkyard based off this list, swapped my PROM into it, and it worked like a charm - no problems since.

 

Cool Thx