This problem is still not resolved. I have done all the checks listed in the GM Shop manual. The key to solving my problem is removing the Code 18. Fuel pressure problems don't case a code 18 to be set. The ERG valve does not cause a code 18 to be set. The code 18 is going to keep the engine running in an open loop mode, so of course the engine is going to idle like crap.
Now, I have swapped out both new cam and crank sensors. I went into the engine and checked the timing gears and chain, the timing had not jumped but a new timing set and damper were installed. The harmonic balancer vanes are all in place, none of them are bent, and I even cleaned them in case contamination was interfering with the sensor. I checked all the wiring and even replaced the computer PCM, with a reman one. I can see nothing wrong here. I even put the old ICM back on just in case the new one was defective, no change.
Something has to be causing this code 18, is sets only seconds after starting the engine. I will be happy to donate or pay for a solution if someone can help me.
Friday, March 16th, 2012 AT 8:20 PM