bucks near WOT but no knock

[dboyle23]

So, at the top end of any gear, my 2g bucks for a second and then continues to drive normally afterwards.

I have attached a log but I get only 1 count of knock.

I have had this problem for awhile. I have swapped out plugs, turbos, intercoolers, cams, injectors, since it began and the problem persists.

I have a 16g running 264 cams, fmic, 660's, and wally 255 not rewired.

Everything looks fine in the pull to me, what do you guys think the problem could be?

 

[EclipsoGSX]

I have the same problem and would like to understand why it's doing this. Like mentioned, it really only happens under WOT. It's a quick buck and then continues to drive normal. Also maybe related, when under a consistent speed of 45 and greater, I feel slight "bucks" at low to no boost levels.

 

[98EVOECLIPSE]

When it bucks, does it just do it one time, or continuously as you accelerate? My friends gsx jerks when he punches it, but it gets worse and worse the more he presses the gas. Doesn't do it at all when driving normally... No idea what causes it. Although he's not running a boost controller either, just let's off the gas at 20psi... Not sure if unregulated boost could be his issue. Interested to know if anyone knows the cause as well.

 

[Imback]

Weak spark would cause what your describing. I once had a problem very similar and went through everything. In the end it was the coil pack.

 

[Cody Nelson]

putting money on plug wires. they loose their internal resistance with age

 

[DynastyLCD]

Weak spark would cause what your describing. I once had a problem very similar and went through everything. In the end it was the coil pack.

^ This. I've had this same problem time and time again, with multiple DSM's... Only to change either the coil pack, or the transistor pack.

 

[4g63t]

Before you do anything, I would try a new set of br7es plugs and drop the gap to .20. I bet it goes away.

 

[dboyle23]

I just put in some new plugs yesterday. I'll try narrowing the gap to .20, if that doesn't fix the issue then I'll go with some new plug wires. If all else fails, coil pack and transistor pack.

Thanks guys.

 

[03RedSRT4]

I have experienced this "buck" before with two cars. My own, and another SRT owners.

My cause was found to be a cracked spark plug body. The spark plug was intact, however it had a crack on the porcelain, above the threads, near the wire.

In another car the cause was found to be an improperly torqued knock sensor. It was very loose.

 

[EclipsoGSX]

Thanks for the information everyone! I'll be narrowing this down soon. I'm going to start with the plugs. I'm not sure what brand was in it when I got it, but the wires are NGK.