Hello folks... I've been battling this miss that is showing up with my 2003 pontiac grand prix 3.1.. I'll try to explain it as well as I can...
90 percent of the time, my car while at idle will have an obvious miss in it. When the car is acting up and I turn it off the key is unremovable without hitting the release under the collar of the steering wheel.. Confirmed with a meter designed to read and confirm the misses as well as they are audible as well. Problem is, it seems to be all of my cylinders missing. Looking at the coil pack from the front of the car going from left to right i'll list the voltages below:
1--15kv - 17 kv
2--5.6kv - 6.0kv
3--2.0kv - 6.0kv
4--2.1kv - 4.7kv
5--11.6kv - 13.8kv
6--14.6kv - 17.2kv
These ranges are constantly in a flux, with reports of miss drops on all of them... I've replaced the wires, plugs, coil packs and even the moduel with ac/delco replacement parts and the problem still persist.. My most recent attempt was swapping out the ecm with one i've picked up at the junk yard which was the exact replacement of the one I had.. Same problem.... But here is the kicker.. Every now and then, the car runs perfectly. And when it does run like this, when I shut the car off i'm able to remove the key without having to reach under the steering column collar to flip up the release switch...
Perchance am I having issues with the ignition system involving the switch? I've replaced soo many things i'm bout to my wits end on this.. Oh, and the computer is NOT throwing up a service engine code about the mess either, and it doesn't appear to be missing while driving, just when I let off the gas allowing the car to return to idle.. Every now and then when i'm switching from drive to reverse this missing makes the car stall out as well....
Please help, or ask any more details you need to know!!!