02 Z24 Cyl #2 mis?

[scaldwellk]

My wife has an 02 Z24 with a 2.4L 4spd Autotrans. I have an OTC scanner that I use on the car. When I hook it up to the car I show a mis in cyl 2 only when I give it some gas. I have just changed the plugs and wires. Old plugs where Autolight that someone had put in for some reason. It has turned the engine light on when the engine is cold. I check the codes and it shows cyl 2 mis. The car only has 53k on it. Could this have been caused by the wrong plugs and it will fix it self in time? Is there anything else that can cause a miss in cyl 2 with these engines?

Thanks

[jayson716]

wires? i didnt think they had wires and no the plugs shouldnt matter just as long as there gapped right. running low oil may have a problem if that happened but ussually the #3 gets messed up

[scaldwellk]

It has a boot like wire from the coil pack to the spark plug. It has now developed a mis in cyl 1 as well. Cyl 2 seems to have gotten a worse mis to it. Could a coil pack or the board that the wiring plugs into for the coil pack cause a mis? I have had it to the dealer and they told me that they could not find anything wrong. The only thing they said was maybe wrong plugs. It is still worse when engine is cold and was real bad tonight. When I first changed the plugs and wires it seemed to have fixed it at 1st, but it came back. I am pulling out my hair over this car. This just has to be something stupid going on here.

[jayson716]

well i know my friends truck has coils and when they go bad it says a misfire. on the code but i ddint know that the 2.4L had coils. but then again you said it was a 02. i have an 00.

[jayson716]

so i guess if it were me i would try to buy a new set of coils and replace them if it still does it put the old ones back in an return the new ones, what could you lose

['94CavyRs3.1]

yep replace them coil packs..the old beater did the same thing started off not to bad but once the pack was dam near done, it was missing all the time...i think there are 2 of them on the back of the motor under the intake? at least they where there on the old car.

[scaldwellk]

The coils on this engine are on the metal cover that says 2.4 DOHC. The coils are on the bottom and fit between the valve covers. I think this is a Quad 4 type engine?? I am going to take the coils apart today and check if there are any cracks in the plastic cover.

[scaldwellk]

Well did a few things today. I changed the coils around to check them both. The mis stayed in cyl 2. Changed the modual that the coils plug into and still mis in cyl 2. I called the chevy dealer and they want to do a compression check. Why would they want to do a compression check on the engine?

2nd part of the story. My wife bought the car with a 30 day warranty. She has had the mis since she bought the car and they have given her a run around about the mis for over 30 days. She is going to see the lawyer tomarrow about what the dealer is doing. The dealer is alittle one in the area that we have found out to have a bad rep. They are not a chevy dealer, car goes chevy dealer Tuesday for them to check. Isn't there somesort of a lemon law to help buyers?

[richtazz]

did you change the module or the coil housing??
The coil housings in those engines are prone to carbon track and cause a misfire, it's possible that the #2 cylinder has developed a carbon track to a different cylinder and is not firing th e#2 plug. Teh only other thing i can think of is the boots from the coil housing to the plug are bad or loose. They look like spark plug wire boots, but hook directly from the housing to the plug, they run about $15-$20 for a set

[scaldwellk]

I had changed the whole coil pack, boots, and module with a complete set up I have extra.

[richtazz]

The coil housing is the plastic piece all those parts bolt into. IF you changed it with the coils, module, boots, then you either have a bad fuel injector, or a compression problem in cylinder two. Bad compression will cause the cylinder to misfire due to lack of combustion chamber pressure ( the air/fuel mixture must be compressed in order to make power), or you have a bad injector not putting fuel in that cylinder, which should be self explanitory (no fuel= no fire)

[scaldwellk]

Originally Posted by richtazz

The coil housing is the plastic piece all those parts bolt into. IF you changed it with the coils, module, boots, then you either have a bad fuel injector, or a compression problem in cylinder two. Bad compression will cause the cylinder to misfire due to lack of combustion chamber pressure ( the air/fuel mixture must be compressed in order to make power), or you have a bad injector not putting fuel in that cylinder, which should be self explanitory (no fuel= no fire)

That was what I needed to know. I will have them check the injectors if nothing shows on the compression check. Thank you.

[scaldwellk]

Got the car back from the dealer today. They worked on it for awhile and where able to get a code from the computer that showed a misfire. They checked everything over good and put new electrical ends on the connectors for the injectors. They even put some dielectric greese on the connectors. It does seem to run better, but I am still able to pick up a slight misfire in cyl 2. I am going to put some injector cleaner in the tank and see if this will finish getting rid of the misfire. If this does not work can I change the injectors between 2 cylinders to see if the misfire moves with the injector??

[richtazz]

yes you can, all the injectors are the same, so you can move them to see if the miss moves with them.

[scaldwellk]

Great, I will try that if the cleaner does not work.
Thanks