The Lumina was running really rough for a day. It then died and could not be restarted. The engine cranks fine. The fuel pressure is 45 PSI at the injectors. A timing light and a spark plug test light both indicate a spark is occuring. The injector signals are changing, but I wasn't able to verify either the duration or the voltage swing of the injector pulse. The CAM sensor was recently changed. The 3X crankshaft position sensor feeds the Injection Module and indirectly to the ECM computer. I haven't changed it or feel I know what the voltage or signal should look like. I tried a junk yard Ignition module and junk yard ECM computer with no change to the symptoms. Could the Crank shaft sensor cause a complete failure? Any other ideas? The only recent code was the CAM Senor activity.
I am having a problem alot like yours I have spark but my fuel injectors are firing weird sometimes they work and sometimes they dont all work if you found your problem please let me know I am taking my car in this weekend ill let you know what I find out
September, 29, 2006 AT 10:01 AM
I found the problem. There was no compression in the three cylinders that I tested. The timing chain slipped gears which was the cause of the lack of compression. While the valve cover was off, I noticed that one of the valves was stuck (not moving). Removing the rocker arm and a tap on the valve released the valve. I still don't know if the piston hit the valve to cause it to stick or something else caused the stuck valve.