Jap Import

Am I hitting fuel cut?

I have a classic STi type RA.

I can floor it up 1st, 2nd, 3rd, 4th but when I go into 5th it's like theres a flat spot.

The revs are'nt high so it cant be the rev limiter.

Any ideas guys?

sparky300

fuel cut does not give a flat spot like that, if you hit fuel cut you know about it, total loss of power (nothing at all) you get a big tug like someone has pulled you back a little, sometimes even a bang as fuel is dumped, then as your revs drop back to a safe level the car comes back to life - thats fuel cut.

to be honest if it were fuel cut then flooring it in 3rd and 4th should do it as well. is your car limited in speed somehow, some jap cars are?

try to see when it happening, it is due to speed, revs or boost? first try the revs, rev up to the same point in every gear, still does it in 5th only, then its not the rev limiter, then try boost, get to your max boost in 3rd 4th and 5th, if it does not cut out in 3rd and 4th the it may not be fuel cut. then last try speed, go to the same speed in 4th and 5th see if it happends then?

ok this is not a very good way to tell, but it gives you a little idea before you pay to hook it up to a computer.

could also be a number of other things so best to take it into some to have a look maybe, take care of her.

sparky300

PS Halfords and other retail outlets sell stuff which can give your car a good clean out to get rid of flat spots if thats what it is. or a sensor could have gone, it the engine light on? any errors?

Jap Import

Thanks guys.

It is like something is tugging me back, but only in 5th.

It's high geared so i'm up the box pretty fast, 1st through to 5th.

From what youve said sparky it does sound like fuel cut, although it cant be as its only in 5th.

As soon as I hit 5th power goes then builds back up.

Prehaps it could be boost.

She goes like mad, maybe Im taking her too high in 4th prior to selecting 5th.

Gonna have a play tonite with 4th to 5th at different revs.

Damn, its hot in this sticky office, looking at her through the window, I wanna go play now

I'll let you know mate

The Chief

I used to have this problem only in 5th - at around 100-110 when booting it, not happened recently though

sparky300

it is like a tug, the power drops off then comes back could be fuel cut.

dont think you would hit fuel cut in 1st, 2nd or 3rd unless really killing ur engine. fuel cut is easy in 4th and 5th if you have been playing with boost!

do you have a boost gauge? what psi are you running, and whats ur car?

Gillp95

Since you have just had your gearbox rebuilt

halfpint

Dose the check light come on when this happens ?
what are the revs at when this happens ?
need more info