avexhype

Lately ive noticed that my 09 GT (auto) wih 41k miles has a miss/hesitation/hiccup under WOT right after the tranny shifts into 3rd gear and is climbing the RPMs.

It seems to do it on a regular basis and can be replicated about 75% of the time. The other 25%, it shifts into 3rd and runs to 4th and 5th just fine.

Any ideas? Fuel pump? Bad throttle body/tps?? TRANNY?!!

PS: I made 5-6 runs at the track the other day and it NEVER did it, not once. The car was doing it when it was bone stock so the mods haven't changed anything.

Mods:
JLT w/ Brenspeed tune
3.73 gears
Mufflers

Nuke

Since it's only doing it in 3rd gear, I'd eliminate the fuel pump as one of the more likely candidates. Before I'd begin looking for a mechanical issue, I'd talk to the guyz at Brenspeed to rule out if it's tune related.

avexhype

Well as mentioned above, it was doing it exactly the same back when the car was BONE stock with no mods at all, would that still be tune related? You can feel it enough to where your head/body will slightly jerk forward, kind of like if you quickly let off the gas and stepped back on it..

Nuke

There is a TSB for the fuel pump related to hesitation/bucking but that was for the earlier years (05-07 or 08 maybe?). It was pronounced following steady state cruising and then going WOT or any other aggressive acceleration. My wife's 06 V6 had that problem. But there is also an issue with the PCM cutting spark with the TCS on and going WOT with any possible wheel spin. I had that a lot on my '07 before I got smart and made it a habit of turning off TCS upon startup.

avexhype

Yea TCS on or off doesn't make a difference in my case. The FP tsb is for after long cruises, doesn't apply to me either.

Looks like its the 3rd gear band or solenoid going out. Gonna have it checked out later this month.