GenVibe - Community for Pontiac Vibe Enthusiasts

I have a base Vibe - 5spd. When I accelerate hard (pedal to the floor) and run the engine up to redline in the gears, I sense along the way up the RPMs a couple of very slight, but obvioulsy noticeable, hesitations in the engine, like a little tiny hiccup. It's more noticeable in first and second gear. Does anybody else experience this and/or know what's wrong? Or is this normal?Thanks!

I've noticed it, too. It seems more noticeable with the A/C on, but that just might be my imagination. I noticed it the first time when I had used some cheaper gas, but again, that just might be my paranoia kicking in. I've gone back to only top-brands of gas. - Earl

I noticed the same thing, what it is if a/c is on is compressor for a/c kicking off causing a burp

I've also noticed it, but it doesn't seem to matter if the ac is on or off. Could be just dips in the torque curve, or the ecm retarding the timing due to it sensing knock from low grade fuel. I almost always buy the cheap stuff, so maybe next tank I'll try premium again and see if it still does it.

quote:Maybe it is the rev limiter kicking in? No, I've noticed a "dip" around 3k. The rev limiter wouldn't kick until into redline.

quote:Is that with the CAI installed too?Ya, seems to still do it.

when does the rev limiter kick in on a 5speed base model? 6000rpm, 6500rpm....? thanks

On my base 5 speed, the limiter comes in at 6,400. I too feel the occasional little hiccups on the way to redline. Sometimes they're more noticeble at part throttle. I think that perhaps the variable cam timing shifts in steps, rather than continuously; or it could be some minor imperfections in the fuel or spark calibration. I've never used Premium fuel, guess I should try a tank and see if affects power or the "hiccups"One of these blips seems to occur at over 6,000 RPM, and I have the feeling the car would be a bit faster if it could be shifted at say 6,800, thus ending up on a fatter part of the power curve after the shift. Guess I won't find out until/unless someone comes up with an inexpensive ECM reflash or whatever it takes for the Toyota computer...