I have a 3.8L and have replaced plugs and wires and double checked all connections but cylinder 5 is still mis firing. Coils have all been tested. Is it a clogged fuel injector? I used some fuel injector cleaner with no change after a tank of gas. Sounds like a back fire when accelerating.Very sluggish. Please Help.

 

prolly the plate thing the 3 coils plug into. its about $150 at autozone.

 

I think h8er is talking about the Ignition Control Module (ICM). Were all the plugs gapped properly?

 

I went through the same thing with daughter's Cavalier. Replaced plugs & wires, and narrowed it down to either coil or injector problem. Fuel injector cleaner in the tank didn't clear it up either. So I removed the injector in the suspect cylinder, put it in a small container and soaked it in carb cleaner for about ten minutes and swooshed it around real well. Put it back in....and good as new. Might be worth a shot for you to try.

 

Same thing here, I have a misfire #3. I thought it was the transmission but it wasnt so I have a brand new transmission for nothing cuz it's still misfiring so they said it might be the injector or something cuz the wires and plugs should be good cuz i had a tune up about a year ago and the ignition coil is also new so I'm not sure but I guess I have to take it to the shop again.

 

did you switching the coil pak to a different spot on the icm? if it follow after the switch then its the coil.

 

Same problem here, getting a trouble code of P 0300 (engine misfire detected) but I don't know which cylinder #, going to try all new spark plugs tomorrow , then take it from there[sm=boohoo.gif]

 

Yea this seems to be a really common problem with these cars...

I am going through the same thing right now. Changed the plugs and wires and it didnt get better. If you pull the wire of off the coil post and have some one start the car for you, you should be able to diagnose if the coil is working or not. Basically, if the coil is sparking to firewall then it should be fine... right? Autozone will test the ICM if you pull it out of the car.

You can do a resistance test of the injectors. If they are between 11-14 ohms than the coil inside has not gone bad. However, that does not mean the injector is not plugged with crap. And running fuel injector cleaner will not necessarily unplug your injectors. From talking to a couple mechanics, fuel injector cleaner is actually pretty harsh on injectors.

I think I have diagnosed mine down to the injector being somewhat plugged. I came to this decision by reading the spark plugs. I might be totally wrong and will find out tomorrow when I put a new injector in.

Basically I came to it as this: The cylinder is not firing. It is either spark or fuel related. Spark and no fuel or no spark and fuel or no spark and no fuel.There is spark at the coil and spark at the plug. After the car has been run for about 10 min and pull the plug; it is dry. Therefore it must be a fuel problem. If there was fuel and no spark, the plug should be wet from all the fuel ran at it.

Ill let everyone know if this fixes it...

 

OK well after a weekend of working on the car, the situation did not get any better.

Changed plugs and wires.

Changed injectors.

Changed coils.

Tested ICM. Tested strong.

Cleaned EGR and PCV.

Fuel pressure is good.

Tested injector connection with a test light. Injector is firing.

Sprayed carb cleaner and propane around intake manifold. No change in idle.




Anybody else have any other suggestions??? I am about out of ideas.[/align]

 

Fellow frustrated Camaro owners, changed the spark plugs, still no joy.Frechles71,did you have a P0300 code? an engine misfire ?(but doesn't narrow down which cylinder)Going to try new coils. I don't even want to drive this thing when it runs like ****! Is there a common denominator?