My car never had much of a hesitation problem when I first purchased it ~6 months ago, but for the last month or so it's been hesitating consistantly in 3rd+ gear, very rarely does it do it in 1st or 2nd.

It seems to have come around about the same time my y-pipe split in two, and I lost one half of my exhaust, and I also put in a good remote start system in shortly before that happened.

Over the last week, I have put in a new Racing Beat replacement y-pipe, but still have a leak because my cat has a split right down the middle. The hesitation has improved and the car runs much smoother overall, but it's still present. I tested the aux. port actuators using lith. grease at the base and seeing how it spread up the shaft as they were pulled in, and the front actuator seems to be going all the way in, but the rear only gets half-way there. Could this be due to poor back pressure thanks to a busted-*** cat?

In addition to replacing the y-pipe, I put in injectors that were sent out to Cruzin' for cleaning and balancing, removed the cold start fluid system and used a block-off plate, re-grounded the battery and 4 new grounds to the ECU, and adjusted my TPS sensor, all with no results. I even went to the point of pulling all my electrical connectors and cleaning the contacts on every one I could get to, no dice.

I can't really think of anything else that could be causing it... I cannot find any vacuum leaks, and my electrical system appears to be in good condition. The voltage stays at a pretty steady 14-14.5v but does drop close to 12v if you hit the brakes when the heater, headlights, and the brakes are hit.

I did play with the BAC valve too just for kicks, and my idle does not drop when the vehicle is warmed up and running all the electrical stuff I can run after you pull the connector from it, so I think that's shot, but my idle is good, which is the only thing I thought it affected (you can click HERE to see it in action).

Thanks for any advice guys. The hesitation doesn't usually drive me nuts because if I were to race *cough*, I only pass the 3k mark once, and it's not having the problem in 1st gear, although hitting 100 or so does bring it into the range and it takes a bit longer to move past that mark on the speedo. It sucks actually watching the tach when you're getting up to speed so you don't hit the 3k mark and get pissed off as well.

 

Exhaust backpressure will not cause hesitation, it just lowers power overall. If your 6PI actuators are not operating together, then you need to pull the LIM and port sleeves so the whole lot can be thoroughly cleaned.

 

Yikes, I'll just leave them they way they are for now then. I'm really getting pissed about this whole hesitation problem though... I think I'm going to dig out my old injectors, clean them out, and see if they help any.

I'm going to pull apart the remote start and make sure that all the connections are still solid as well, although I don't see how that would be causing my problems. It just piggybacks on the two ignition circuits, pulls a 12v from the ignition switch, and grounds to the chassis above the brake pedal. Oh, and the starter runs through it, but the ignition still pulls from the switch like it did in stock form.

I just checked the timing as well, and it's looking good, dead on. Any other things that I might have missed?