High rpm studder

[imp pwr online]

I Can run from 14 up to 22psi. O2's stay constant and solid-never deviating at any rpm. EGTs are all good. Knocksums stay at 0-4 thru out the rpm range. Everything on the logger stays constant even when this happens.

At WOT, every time when it hits 6,000rpm (redline is 7,000) it starts sputtering, like it's missing. On the logger, O2s are still solid, Knock is still 0, you can see when it hits 6,000 it is still WOT but instead of rpms climbing they start flatlining bouncing from 6200-6000. Just bouncing around cause the hesitation. But O2s stay, knock stays. Nothign on logger shows anything is happening except that it is still WOT and not climbing RPMs.

I am using copper plugs since plats are to hard to fire and cause blowout too easy. They are gapped down to 34 (factory is 42)

But I did turn boost down to 14 and still happened so I don't think it is blow out.

Any ideas?

[Hans91GT]

Check the plugs to make sure they aren't fouled out. How does the timing look when you are in that high rpm area? Does it change a lot from normal (since the numbers aren't really the actual timing value).

[imp pwr online]

Timing is no different than before 6,000

New plugs

About 1,000 miles

Copper bpr7es

Gapped 34

Happens wether at 14 or 18psi

Factory wires, don't know how old

[Hans91GT]

hmmm, at .034 it might still be too large for 14 psi. I would check to see how the front bank plugs look.

Factory wires have the production year on them about ever 6 inches or so :).

[imp pwr online]

Originally posted by Hans91GT
hmmm, at .034 it might still be too large for 14 psi. I would check to see how the front bank plugs look.

Factory wires have the production year on them about ever 6 inches or so :).

For plats it was but not for copper. Hell I had plats gapped to 28 and still blew out around 18psi. Coppers spark easy and no blow out up to 22

Turned out to be my HKS S AFR freaking with things...All better now!

[DJ Eric P.]

Hey, IPO I have a 91' VR4 also. I see you have a big mod list. What are you running at the track? Do those 17G tubos make a big difference from the stock ones and if I were to get bigger turbos what would I need to complement them.

[Puma]

IPO,
I had my plats gapped at 27 (AEM recommends 0.027 for boosting up to 20psi) and was able to boost to 20 psi and hold 20 psi to redline.
Unfortunately I started messing around with my fuel map making it run richer for around town driving and apparantly fouled my plugs. I installed the CTC coils and wires but no help there.
Tomorrow I will get the new plugs installed. Hopefully this will restore full power to my car.
Ron aka plaides