I think I solve my idle and bucking problems. Maybe this will help someone else too.
I have been fighting this problem since I took it out of storage in April. It idled like poo and would have bucking under part throttle. Sometimes on WOT but not usually. I was thinking it was due to upgrading the MAF and injectors last fall, but it was running OK then. So I have been playing with my Tweecer for that last couple of weeks trying to find something in the tune out of whack. I wasn't having much luck until I decided to datalog it. I don't like datalogging with my laptop because it is a POS and don't like being jostled around. I had trouble getting it to work, but eventally I got about a 10 minute log with about 5 instances of the bucking. When it was bucking I saw the MAF was all over the place, both very high and very low. So I checked the plug even though I had several times already. Even though it was plugged in, due to a broken tab on it, it was just lightly pulled out. I locked it in with the half of the tab that was left, and NO MORE BUCKING and it idle smooth again!
So my lessons learned: Don't assume a connection is good just because it looks good. And datalog right away if you have the ability. It made finding the problem easy in hindsight.
And don't just start throwing money at it either! I didn't, but I considered new o2 sensors (even though mine are new), switching back to shorty headers, new injectors, new dizzy, and just saying the hell with it and buying another 2011 GT (manual trans this time!). All over a 5 dollar pigtail!
I have been fighting this problem since I took it out of storage in April. It idled like poo and would have bucking under part throttle. Sometimes on WOT but not usually. I was thinking it was due to upgrading the MAF and injectors last fall, but it was running OK then. So I have been playing with my Tweecer for that last couple of weeks trying to find something in the tune out of whack. I wasn't having much luck until I decided to datalog it. I don't like datalogging with my laptop because it is a POS and don't like being jostled around. I had trouble getting it to work, but eventally I got about a 10 minute log with about 5 instances of the bucking. When it was bucking I saw the MAF was all over the place, both very high and very low. So I checked the plug even though I had several times already. Even though it was plugged in, due to a broken tab on it, it was just lightly pulled out. I locked it in with the half of the tab that was left, and NO MORE BUCKING and it idle smooth again!
So my lessons learned: Don't assume a connection is good just because it looks good. And datalog right away if you have the ability. It made finding the problem easy in hindsight.
And don't just start throwing money at it either! I didn't, but I considered new o2 sensors (even though mine are new), switching back to shorty headers, new injectors, new dizzy, and just saying the hell with it and buying another 2011 GT (manual trans this time!). All over a 5 dollar pigtail!