I have a 99 Camaro v6. It started misfiring after I found that one of the spark plug wires was cut down to the bare metal in a small section. So I put on another wire that didnt really fit it. I drove it for alittle while until I got new spark plugs and wires. Well I put them on and its still misfiring. It hesitates and stumbles really bad accelerating. I have no idea what else it could be. I checked the ignition coil secondary resistence and its good. Before I noticed the cut wire it didnt hesitate all the time like it does now. It ran well and only hesitated rarely. But now it runs like im in a much higer gear and its bogging. But if I slowly increase speed it doesnt miss much. Any ideas? Also its not throwing any codes. No check engine light at all. Ive even checked it with a obd2 tool. Nothing.

 

Did you by chance cross wire it when you replaced the plug wires?

 

I thought that too and traced them back to their places and they matched up with what my book says and how they were before. I did notice the ignition coil for 3 6 had been replaced and the other two were moved around before.

 

My guess is you have a weak coil pak, if you have replaced the plugs and wires and have no codes. My understanding is that the coil pak fires both cylinders at the same time so if one is going bad or is bad, then you probably feeling like a 4 cylinder. I am assuming fuel pressure and filter are good.

 

I was thinking coil pack too. How can you tell if they are bad?

 

If you have a Haynes manual, there is a test with an ohm meter to test resistance on the primaries and the secondaries of the coil. Also, if you have a spare plug and plug wire, you can snap it on the coil and ground the plug. Have someone fire it over and check for a bright blue spark. Make sure you ground it good. They bite hard.

 

I checked the resistence on all the coils and even replaced one because it was cracked and had rust on its terminal. But that didnt do anything. I replaced the icm but that didnt do anything. So I am thinking fuel injector, timing chain, or possible the other two ignition coils under load are failing. Because I have absoltutley no Check engine light!! Im very frustrated.

 

Sorry I meant to say I checked them and they were in the zone that they are supposed to be at.

 

JUST WONDERING IF YOU FOUND THE PROBLEM, AS I SEEM TO HAVE THE SAME TROUBLE, THE CAR RUNS ROUGH EVEN ON IDLE (its a 94 3.4 camaro), AND WHEN YOU ARE ACCELARATING TOO FAST ITS NOT GOING FASTER, IF YOU ACCELARATE VERY SLOWLY ITS SORT OF OK MOST OF THE TIME..........., ANY IDEAS ANYONE ????????????????

 

This happened to me i went thru like u did and followed the wires to make sure replaced my cracked coil pack looked at all the new plugs to make sure i didnt crack any and then i replaced my wires and it fixed it. it is possible that when u were trying to get ur wires back on you might have ruined them. this is assuming it ran fine before. if it did then the problem really shouldnt be your timing chain or injectors unless u messed with them or you just have really bad luck and its all breaking at once