1991 Camaro

Its a 3.1 V6. For some reason my car is running rich according to my Autoxray scanner. All the sensors seem to be in spec, however, the ECM want to keep the CCP (evap or charcoal canister) OFF all the time which means the ECM is constantly purging the gas vapors back into the throttlebody. It will not go to the ON signal at all no matter what the driving condition. Any thoughts?


The Charcoal Canister Purge constantly OFF indicates that the ECM has decided that to open the purge solenoid would just add to the ‘running rich’ problem. I am not that familiar with the evap plumbing on the 1991 Camaro. Does the canister vent air exit to the throttle body ahead of the throttle plate?

BTW is the CEL ON at this point? What are the exact codes being shown by the Autoray scannner? Check for fuel in the fuel presssure regulator manifold pressure line going to the intake manifold/throttle body. That could the source of the extra unmetered fuel getting into the system.

Hope this helps.

Well…I’m not getting any codes. The line coming from the canister goes to a spot behind the throttle plate. Seems like I pulled the vac line going to the fuel pressure regulator to look for the presence of gas, but didn’t see any. Car runs like its got a “miss” to it even on a cold startup from sitting all night. My BLM is at 100 and the INTEGRATOR is usually around 95 on the open highway. While at a stoplight, the INTEGRATOR will be at 128 and slowly drop to 100 and below that it idles crappy, The ECM will compensate and bring it back to 128 but it continues to drop again. Injectors might be gone or have a bad spray pattern. Kinda strange the CEL never comes on.