Help With My Car.....i Think The Term Is Surging?

[nsta]

Hey guys, ive got a 94 R33 SKYLINE, and when wot, after around 4500-6000 rpm, the car may give me a sudden jolt for a split second, and then go again, then maybe another 1000rpm and itll do it again, this is when im giving it WOT.

What exactly is this im experience, i think its surging but cant be sure

its an r33 gtst (series 1 rb25det)

mods:

3"exhaust to split dump pipe

FMIC

apexi pod filter

stock ECU

boost tap running ~12psi

i have a bosch 040 pump aswell, that has yet to be put in.maybe the car needs a tune now?

[zebra]

Could be missfiring? whats your plug gap?

Id put in the new pump and check again.

Also how much fuel was in the tank

Very Much sounds like Factory fuel/boost cut Mine did it at about 10psi with the stock computer....my head nearly hit the steering wheel at 4000rpm.

[aDrew_C]

Sounds like boost cut.

[Cubes]

No such thing as boost cut.

Fuel cut.

[R31Nismoid]

Stock ECU + 12psi = thats your problem

Back it off to 9psi and you'll find the problem will go away.

Just the normal issue when using a stock ECU. Furthermore, you should not be running 12psi on the stock turbo

[nsta]

Alright, ill try that and see what happens:), thanks guys.

Is it a limitation of the stock ecu, and should i get the fuel pump installed anyway?

Um...my coils are gapped at .5mm to stop the missfiring, which i knw sounds ridiculous, but its the only way for it to stop!.

Ive since ordered splitfieres which should be hopefully arriving soon.....will gapping back to 1mm with the splitfires increase performance on the same boost?

[Xizor]

Can someone explain the surging to me?

I am having real problems with my car at the moment is freaking me out i was just meant to go to work in chatswood and turned around and went home i was scared! I have r33 s2 stock turbo @ 12psi mech controller, fmic, turbo back zorst, pod. Its been fine pretty much had it at 12psi for over 6 months. But it gets this sort of stuttering during acceleration/spool, typically when i DONT put my down enough for high boost, which can be REALLY alarming sometimes and the car jolts. Its freaky. It only got serviced 2000km ago. It happens mostly in 2nd, but a bit in 1st and 3rd and can kinda tell some other times too just alot more subtle. Its also idling a tiny bit funny i think.

I was thinking my fuel pump, its stock and car has 99k kms? Now im thinking afm? Or boost controller? I dont know. If my 12psi was a problem logically i would think i'd be experiencing the problem max boosting but thats not the case in the least.

[TTT]

Xizor - AFM.

take it off, clean it with electronic contact cleaner.

You can also use degreaser.

when I did mine, I only had degreaser.

so I took it off the car, degreased it, washed it out with slow running water.

Got the wifes hair dryer and dried it out completely.

put it back on the car and it was fine.

Some people also have a problem where the internal connectors have broken off and need to be re-soldered. that is also easy.

but try the cleaning first.

if you bother to go get electrical contact cleaner, you don't have to wash it out and it dries by itself.

you can probably find it at places like Tandy, dick smiths or Jaycar.