Formulals187

iTrader: (3)

Whenever I drive and I'm trying to easily accelerate around 30mph to 50mph the car shakes/stutters like its misfiring, but there is no misfire code thrown. This happens while the car is in 4th gear, 2 weeks ago it threw a misfire code, but I didn't write down what cylinder it was cuz I'm a genius, I cleared the code and drove back to Houston and haven't seen the code since. I have pretty new spark plugs in there gapped to .035. Is the car probably misfiring, what to do to fix it?

LS6427

iTrader: (2)

Very common when people change spark plug wires or do a spark plug change that when they install them....one of the wires is touching or banging up against an exhaust manifold pipe. And the most common problem is a misfire at mid-to higher rpms...not at idle or down low. And, you will only get a misfire SES light or code sometimes like this.

Also, unless your spraying nitrous, your gaps are too small. You should be gapped between .040 - .060. Perfect is in the middle at around .050 for N/A.

But I think your problem is a spark plug wire touching a pipe, since you just did a plug change and them all off.

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Formulals187

iTrader: (3)

All of the wires are connected and none of them are touching the headers, the plugs are like 4-5 months old

LS6427

iTrader: (2)

Only other things that I can think of that misfires or causes stumbles mid-high rpm ranges are cracked spark plugs or maybe a broken spark plug wire.

Dirty MAF would cause it at close to and at WOT only, not partial throttle acceleration, IIRC.

Leaky fuel injector. Or one or two clogged injectors.

Probably more...but thats all I got right now.

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LS6427

iTrader: (2)

Next time log which cylinder it is and weed things out from there....much easier.

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Formulals187

iTrader: (3)

How would I check for leaky injector or anything of that nature?

LS6427

iTrader: (2)

Take the injectors out on each side still attached to the rail. Turn the key to "on" so the fuel pump pressurizes everything and see if any of them drip.

I guess you could also just do a regular pressure check at the rail port with the engine off and see if the fuel pressure drops off after you prime it.

But it could be leaking at those speeds you mentioned and it may not leak until the higher pressures happen when you accelerate.

Thats why I'd figure out what cylinder it is thats throwing that code the next time you get it.....then swap that injector with another cylinder and see if the misfire code follows that injector to the other cylinder.

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Formulals187

iTrader: (3)

Should I regap the plugs that I currently have or should I buy new ones the plugs should only have a few hundred miles on them.

LS6427

iTrader: (2)

Just regap the ones you have in there, they are perfectly fine to regap.

Do .050

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Formulals187

iTrader: (3)

The car does it randomly, sometimes it will stutter around the 30-50 mph range and other times it won't. I'm driving the car similar style and same roads.