my 97 gt has a missfire at 4000rpm under heavy acceleration sounds like a popping sound. Mods are c&l cold air, c&l intake elbow other than that it is stock. The car has 61k miles and the plug wires were replaced by the previous owner with belden 8mm wires. The cel has not activated once and the car passed e-check no problem. Any ideas or suggestions would be appreciated.
97 gt missfire problem
- Thread starter tri5333
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Probably 90% of misfires are spark plug & wires related. I had some top of the line Rousch wire one time that only lasted 2 years!
If you can do your own plugs, buy a new set, check the gap & use a torque wrench to set them. If that doesn't fix it, change out the wires.
If you can do your own plugs, buy a new set, check the gap & use a torque wrench to set them. If that doesn't fix it, change out the wires.
Is there any hesitation? If not then you may have detonation issues. A consistent misfire usually throws a code.
A bit of a long shot, and definately consider the plugs and wires first... but you could try cleaning the wire in the mass air meter. It may be so lean at 4000rpm that it starts missing. Certainly, a pop is not normally found with an ignition miss.
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im not sure about mod motor c&l maf's but ive not had any luck with em on push rod motors. maybe thats your problem.
Im saying possible valve spring because of his 4000k miss. Usually a plug or wire [usually the cause of a miss] will miss regardless of rpm or load. I found in the past with a overhead cam 4.0 with same issue miss under load the valve will float at high rpm because it cant fully close tight because of the spring cracked but run ok at lower rpm. Just something to look into. Your popping noise is what makes me think this. Good luck
schoffs, whenever I've had a miss due to plugs/wires it seems to only happen under load, at higher rpms. If you take it real easy, you don't hear it. When you nail it, that's when the problem seems to occur.
Just my 2 cents.
Off topic: When are we supposed to replace the coil packs on our 4.6L ?I have 104k and they seem to be fine.
