Hesitation/Misfire/Hiccup around 3800 RPM with AC on, under load.

[jhupka]

Does anyone else have a slight hesitation/hiccup with the engine when their AC is on? I usually get it when accelerating, and most often see it in second gear since that's the only gear I normally hit 3800 RPM under load. It is almost like a small misfire or the AC compressor is going off/on. Pretty much always happens at 3800 RPM, and it is fairly repeatable. I can't repeat it at all with the AC off.Thanks,Jason

[Mase]

Are you sure it's a misfire? That should flash your MIL in the cluster if it was a true misfire.Most small Toyota cars will shut off the a/c compressor when the engine is floored and under load. This is to eek out every ounce of power it can produce and prevent overheating. That transition will often produce a noticeable jump in acceleration. I know in my XRS I feel the a/c shut off at around 5800 when it's floored. An auto Corolla and Scion TC that I test drove did the same.

[jhupka]

I don't know if it's a misfire or not...Not sure how else to describe it. You know how sometimes an older car may have a rough idle? It's kinda like a single instance of rough idle, but under load and at 3800 RPM. It could be an A/C compressor thing...but I don't really gain power. It feels like a 1/4 sec of less power, then back to normal.I'm not sure if I'm making more of what it could be...There's only 1200 miles on the odometer, so the car is very new. I just want to stay on top of anything small in case it turns into something big.Jason

[DavidPIL]

Hiya...Yeah, I notice something similar though I don't know where it happens exactly in the RPM range. Only with AC though it does feel a bit like the VVT steps as you accelerate but with a noticable drop in power. Seems to happen more for me when there are 2 or 3 others in the car. Probably normal being that it only does that with AC on and strong acceleration.Dave

[slowvibe]

is your car a GT? if so use the Gt thread to let all us Gt owners hear about the problem. my Gt has similiar but more serious stumbling under full throttle issues.