Pontiac Repair: 96 pontiac sunfire #2 clylinder misfire, head gasket problem, compression gauge

Question
I have a problem with the check engine light on so i have changed the plugs wire and ignition coil light still on.  What next can I do as a do it yourselfer?

Answer
Hi Clyde:

well a few things to check. check compression in the cylinder with a compression gauge and see what you have. Check all 4 cylinders. ther should not be more than a 10% difference from the highest to the lowest cylinder. If the compression is low put a few drops of oil in the cylinder and try again. if the compression returns you have worn or stuck piston rings. if it the same it's a valve issue or a head gasket problem. If the compression is goo you need spark and fuel for that cylinder to fire. Get a spark tester and check for spark on that cylinder.. i'm sure it has it but you never know if it didn't have it #4 would be misfiring as well if it were a coil/module issue. They chare the same coil. Lastly is an injector. You can try a few things. A computer safe test tight hook it up to the injector harness and crank the car and see if the lamp lights when you running the car the computer is driving the injector on. then I would look at a plugged or dead injector. You can take a long handeled screw driver and hold it on the injector with the car running and put your ear on the handle and see in you hear the injector turning on and off. compair the sound to the other ones. Good luck :0