hesitation under acceleration

[Juanmiguel]

Hey all,

My GTP has been doing this for a while and I can't figure out why. It sometimes hesitates under heavy acceleration and you can hear the exhaust go like: "pft", I took a couple of videos, but you can't hear it there.

Please note how the tach makes short pauses, specially in 2nd gear. I just put in a new O2 sensor today to see if t helps, but looks like it doesn't.

Sorry the videos are sideways, I had to hold my phone with one hand...


YouTube - gtp1.mp4
YouTube - gtp2.mp4
YouTube - gtp3.mp4


Thanks!

[FastestGTP]

Do you have a missfire code?


If so I would check the sparkplugs for small cracks in the ceramic. Spark plug wires. Coil packs.


Those are the most common things. My bets on the plugs. Look closley when you do look at the plugs. Some times the cracks can be small.

[Juanmiguel]

No missfire codes at least the SES light doesn't blink, but I can scan to see if there's any. The plugs are new, i just put in new 104's a couple of weeks back when I dropped pulley size.

One of the coils was replaced early this year and the wires are like a year old or so. Maybe I could try replacing those, but I would also guess it's related to one of those things.

[matt5112]

do you still have your cat?

Put your ear to the tail pipe, listen, you should be able to hear the misfires if there are any.

The code doesnt always throw even if there is a misfire.

[Juanmiguel]

CAT's gone and I also replaced the resonator with a glasspack today. Should I be able to hear them in idle too? I don't notice any of it at idle, but i'll check.

[matt5112]

I was always able to hear the misfires at idle.

Gotta put your ear to the tailpipe though.

[Juanmiguel]

Ok I checked the exhaust tips, but I'm not sure I can hear a miss fire, please take a look:

YouTube - gtp exhaust.mp4

[Ricky21]

MAF sensor, try cleaning it if that doesnt work you might need to replace it.

[matt5112]

sounds clean. Lemme check those other videos out...

Yeah thats odd. if it is the MAF, you cant really unplug it and try because the VE tables apparently dont have WOT fueling so you'd run lean... Lean is bad.

[Juanmiguel]

Oh, that was one of my plans to test the MAF, unplug it. I cleaned it like a month ago, but I guess then it would be faulty.

Would it be worth it to tap into the MAF cables and see what's the reading?

[gtpinsc]

whens the last time fuel filter has been changed? did u notice any white colored electrodes on old spark plugs when u changed?

[Juanmiguel]

fuel filter is one year old. the plugs where fine when we changed them. could that be it?

[gtpinsc]

i was just curious... thought it could be running lean and starving for fuel... but white electrodes are a sign of running lean.

[Juanmiguel]

I guess the closest bet could be the MAF, but those are expensive. I'll see if I can find a used one to see if that works.

[SlowNA06]

Vacuum leak? Hear any whistling? I've seen the t-fitting come off the left side between the alternator and coil packs if you've got plug wires routed under your snout and they bump it.

[Juanmiguel]

Yeah I also changed ALL of the T's and vacuum lines a couple of months back when I installed the boost gauge, they where all either cracked or clogged LOL!

[Pshnmeawy]

I have a 3.1 pulley setup and I get a hesitation at times too... mainly during the hard acceleration. Don't get no "poof" or anything, almost seems like the belt is slipping on the pulley. Maybe check and see if that's an issue?

[boosted97]

Could be crank position sensor.
Take your coil packs off one at a time and make sure theres no corrosion anywhere.

[matt5112]

I have a 3.1 pulley setup and I get a hesitation at times too... mainly during the hard acceleration. Don't get no "poof" or anything, almost seems like the belt is slipping on the pulley. Maybe check and see if that's an issue?

thats because your engine is about to explode.

[Fivefingerdeathpunch]

thats because your engine is about to explode.

booooooooooom