WOT Stumble but rolled on WOT ok???
 

Well, this is a weird one that just popped up.

If I gradually roll into the throttle to wot, the car runs fine. But if I, especially at lower revs, put it to the floor it sputters and stumbles and then after a bit will gradually start to go up the revs. However, boost builds fine even while sputtering and revs lag especially around 4K rpm.

So why the difference in putting it to the floor and rolling into wot gradually?


I recently cleaned the engine bay but that was a few days ago so should not be water issue???

Wires are new, plugs about 6 months but cap and rotor are over due.

cap and rotor did that for me

Was having a similar issue on my car last week, it actually started to develop after my track day two weeks ago but got progressively worse. I checked the cap and rotor which both have about 22k miles on them..both of them need to be replaced. The contacts on the cap were very burnt up and the rotor is pretty worn down. I sanded all of the contacts down with emory cloth (cleaned off the carbon..etc) and gave them a good cleaning with brake cleaner. The problem has not come back since, but i do have a new cap and rotor on the way as i dont feel 100% confident going full boost because i am always anticipating the stumble / cutout.

Thanks guys! That is what I assumed since my cap and rotor are the only parts needed to be changed.

Although, this got me looking at some MSD ignition parts. ;)

+1 on all ignition parts including plugs

Todd - here I go again.
I guess I am a broken record.
You have converted AFM chips and you are using them with a Hitachi 90 MM MAF.

I believe I have been telling you this for what? FIVE years??:roflmao:
You need correctly married software and hardware.

Naa, I'm gonna keep it like this just to annoy you. LOL

I agree, but have not found anyone to marry my equipment with a chip. Can you recommend someone :p

Also, your theory would prove correct if the issues I post about are constant. They are not and are fixed by some other issue. Like this is probably because my cap and rotor are several years old.

I'm in DC area now and your in CT. I'd have no problem at all with you coming down and sort my car out; without just writing a blank check to some vendor. :)

I had a similar problem. Cap and rotor took care of it.

I hope so otherwise ST is going to really bust my balls!!! lol

:lol: He likes balls.:nono:

I've had this problem for a while now. All new cap/rotor/wires. What else could it be?

Cap, rotor and plugs = all fixed!

Mike, did you try plugs also?

TPS?

Also take a look at your fuel filter. It may need to be replaced.
I doubt it's the TPS.

fuel filter in new...wires new...