Thread: slow rpm increase with WOT

Hey, so I've got a 2007 base GP, 86000kms that I just bought last November, (actually bought it on my birthday ). I noticed even from when i test drove it that if I just floored it it would slowly accelerate and my rpms would take 30 seconds or so to go from 2500ish to 4500 for a gear change. However if I only put the pedal down a little, say 10% travel, then I get a massive spike I'm thrown back in my seat and the car takes off until a gear change then I need to find the sweet spot on the pedal again for that gear. Most of the time once I get past 80 kmh its always slow accel, sometimes I can kind of play with the throttle (let off then push down a bit) to find the spot to again make it take off but its harder. Anyone know what might be causing this?

You cant really go by "seat of the pants" feel when trying to judge acceleration times. Going by "feel" can be very mis-judging. The best thing to do is to do time trials with either a stop watch or goto the race track.

Yeah, I meant to do some 0-60mph tests today but I got rained out. Unfortunately I don't really know of any tracks in my area sadly (I'd love to hit one for a day), then I wouldn't be trying to do my tests in fear of the cops haha.

Correct me if I'm wrong but shouldn't you get max acceleration when you drop the pedal to the floor?

at fivefinger: There are no lights on the dash and I had my buddy use his Diablo tuner to see if there were any codes stored in the memory and he said there were none. I actually cleaned the throttle body 2 weeks ago. I disengaged the air flow hose (sorry for lamens terms here), the larger diameter hose where the air enters the throttle body. I got a bottle of sea foam deep creep and scrubbed like no tomorrow with a couple of toothbrushes. It started raining later that day so I didn't get to drive it hard to clean out the carbon and after work that night my car wouldn't start for a few tries. As for cleaning the MAF, how would I clean that? Isn't it just an electrical sensor before the TB? Lastly About the cat converter; I've just run a can of Sea Foam through a quarter of a tank about a week ago, as well as my friend and I did the Sea Foam through the engine via the brake vacuum line so I'm trying to clean everything out as best I can, would that have cleaned up the cat at all?

As for warranties it had just passed its drivetrain warranty from the manufacturer when I bought it but I bought the 5 year warranty from the dealership (I got the car from a GM dealer) so if there is anything wrong I can get it fixed, the warranty I got covers everything, bloody everything.

So here is the one picture I'm allowed to add of what I did when I cleaned the TB. IMG-20130623-00110[1].jpg If anyone knows how to add more than one pic that'd be great. But anyways, that center ducting is what I disconnected to allow access to the throttle plate and body. I had to also pull the little hose that goes from the ducting to the engine out (pulled form the engine left attached to ducting), but I made sure I reattached everything.

I picked up a can of MAF sensor cleaner today and right now I'm about to go take it all apart to clean it.

Little update. I took the TP off and gave the body and plate housing a good scrubbing. I may as well do a small review here, I used seafoam deep creep again and let me just say, don't ever bother with it lol. I'm not sure if the deep creep added anything or if it was all just the scrubbing. Canadian Tire sells a throttle body cleaner but I'm not sure if it's too abrasive for seals sensors etc (CRC Throttle Body Cleaner | Canadian Tire) I could only clean as far in as my fingers would allow and I would like to get something to clean in farther but I didn't want to spray anything too harsh in without getting second opinions. I don't have my pictures ready yet but I'll get them up tomorrow. While I had the air ducting off I sprayed the MAF sensor, after everything was said and done the car feels smoother and a little more responsive. I still want to do some tests before I give a final word on it but it feels a little better.

Dont forget to clean the IAC valve most people do. and btw NEEEEVVVEERRR EEEVVVER use a torque wrenchs upper or LOWER values if your torque wrench goes down to 20ft/lbs at the lowest and you need to torque 20ft/lbs use a different torque wrench. only torque within the 25-75% capacity of the wrench if you go outside that range 9 times out of ten you will break something (as you found out) because it is very inaccurate outside the 25-75% range. just so you know for next time