Need Help!!!!

I am working on a 2000 Alero 2.4L. I have changed and checked everything with the ignition system including wires, plugs, coil packs, crankshaft sensor, and control module. I also replaced the fuel filter. I am still getting a very rough idle, multiple cylinder misfiring code and the car will not tack over 3,000 to 4,000 in neutral or run more than 30 mph. I have not checked the fuel pressure at the motor. The fuel pump was replaced about 4 months ago. I am out of things I know it could be. I need help. I have tried injector cleaner and do not want to replace anything else unless I know it will help.

Overheated ? Problems get progressively worse or magically appear?
My first fear is that the 2.4L is a glorified ravamped 2.3 Quad4 with the same issues as its predecessor. I know you stated you checked coils/wires. If this is the IDI system, did you check the coil cover for burn marks/cracks? Its hard to balance test an IDI system since the plug boots are covered.

It does not overheat just idles really rough and cuts off after about 8 mins of sitting idling in the yard. I have not replaced the coil housing but i check it for cracks and checked the continuity of the leads. All checked out good. I also did a compression test and all the cylinders were about the same and all within manufacture specs. I had two codes one was not in any book and the other was multiple cylinder misfires. I'm leaning to a fuel problem but want to know if anyone else had these problems and what was wrong.

I really need someone help on this. Could it be a computer problem or fuel or what? Anyone that has had anything like this please help.

Josh

There is a good possibility that there is a problem in the ignition system that you couldn't detect. Since you didn't say what you replaced then make certain that you put in new plugs and boots. The most common cause of misfires has to do with the plugs and wires or boots in your particular application. Also replace the cam sensor. It is easy to get to and could be part of your problem. It would be good to check the fuel pressure although I suspect part of your issue has to do with the catalytic convertor. If the engine won't rev then there may be a problem with the cat being clogged. Unhook the cat and see what happens. If it is bad you should know almost immediately. They do plug up and can cause a lot of the issues you indicate.