stuttering sti

[predator]

Hi guys

I have a bit of a problem with my Sti. This problem keeps recurring but only at track days. It's happened to me at Pukekohe a few times and today at Hampton Downs.

After about 20 laps or more (not continuous) when I accelerate out of sharp corners from low speeds (>50) the car starts to stutter and feels like it's hit the rev limiter as I accelerate. This happens at low revs 5/6000rpm. When I lift off and then floor it again the problem is gone. I can't make it happen by driving the same way through the corners - the car just decides to do it.

I'm not sure if it's misfiring or the clutch, diff or gearbox is stuffed.

I recently had the on board cpu diagnostics checked out and the were no fault codes showing so I don't think it has to do with the engine. But then again...

The car pulls perfectly and drives fine otherwise.

Any help will be much appreciated.

Thanks

[Guest]

low fuel causing it to not pick up enough?

-smurff

[Koom]

I've had a similar re-occurring issue at the track for years. I think its not an ECU issue as I have a Possumlink. I've re-done the wiring to the fuel pump and re-earthed the ECU recently so need to test if that has helped.

I used to get it after the hairpin at Ruapuna on the second hot lap in every moring session, after lunch I'd usually fill with Avgas and it would eventually go for 10 or so laps consistently without the hesitation. Mine never cleared once it starts though (had to park up for a bit).

I often wondered if it was coils overheating (I use GTB internal ignitor coils) but recently WRXER had a similar issue in his car that runs external bosch coils.

[Guest boostin]

How full or empty is the fuel tank when it happens??

[predator]

I had about 1/4 of a tank left. It wasn't close to empty for the reserve light to come on. My first thought was fuel...

At Pukekohe it would only happen at the hairpin after the back straight and not regularly either. Maybe every 2nd lap.

[madmike]

Sounds like fuel surge to me..

My BC will do it at Manfield with half a tank if i chuck it around to much..

Try putting a bit more in the tank and try some different lines.

[Koom]

 predator said:

I had about 1/4 of a tank left. It wasn't close to empty for the reserve light to come on. My first thought was fuel...

At Pukekohe it would only happen at the hairpin after the back straight and not regularly either. Maybe every 2nd lap.

Right handed corner. 1/4 tank. Thats just fuel surge.

Will do it with anything less than half a tank if you can get the car to grip well.

Dammit, I thought maybe someone else had similar issues to me :'(

[Guest boostin]

Keep doing it and you'll melt pistons. Refuel when you hit 1/2 tank, or fit a surge tank.

[predator]

Mmmmm.....melted pistons. Must run more fuel

[Guest SPANKU]

i had this same problem ever since i had my coupe. it was worst on the track and keep thinking its the fuel even though i have full tank of gas. and then i replace the fuel pump and all the rest of the sensors in the engine bay. i finally fixed after i replace the manifold with another one ussing different tps, ivc and throttle body. it also could be the wiring on the inlet manifold. who knows my problem been sorted after replacement a complete inlet manifold