i have a impreza uk 2000 problem when going in high gears as if the turbo cuts out for a second then back on this only happens in 4th and 5th gears at high revs i thought it might have been air flow problem i have removed air flow sensor and cleaned with carb cleaner still no joy. anyone any ideas?

 

Fuel cut? Or have you hit the rev limiter?

 

its as if the turbo cuts out the back on again. deffo not the limiter mate.

 

its also only when the pedal is flat 2 the floor if u have its half way it doesnt do it and i always try 2 put super unleaded in it but if i put normal fuel in and it makes it worse. ???

 

fuel cut it sounds like

 

wot is causing this??? any ideas?

 

over boosting

 

maybe the fuel pump is wearing.... try changing the fuel filter first

 

maybe is overboosting, have you got boost gauge?

 

no i dont have a boost gauge mate take it i need one to see if its over boosting?

 

yep

 

thanks buddy. wot should it be running at do u know???

 

over boosting its like hitting a wall and then boost back again, specially in 4th or 5th gear

 

Thats exactly it. Thanks people!!!

 

try to clean solenoid and vacuum pipes to turbo, use search button, many treads about it

 

We can't answer that until you tell us what model year your car is. In general pre-1997MY cars should do around 0.75-0.8 bar (11-11.5psi) when accelerating flat out in 4th/5th and 97MY onward cars 0.9 bar (13.5psi) under the same circumstances. An boost level greater than 1.1 bar (pre-'97) or 1.22 bar (97 onward) would be sufficient to trigger the emergency fuel cut - which it certainly sounds like you're suffering.

If you are suffering overboost there are a number of potential causes and fixes but again we need to know what model year the car is in order to advise you. Would also be handy to know what the nature of the problem is - for example whether you've just bought the car and it's been happening since you bought it, or whether it's just started happening all of a sudden. The more we know the better equipped we are to advise you.

 

mine done exactly this mate normally around 75mph but it was over boost on mine causing fuel cut, theres a simple way to fix this sure Richard will be in soon to help solve the problem ( fiesta Boy ) lol something to do with a restrictive thing in a line comin of the turbo.

 

As stated before it depends on model year, but if pre 97 then it may be the coil packs.

 

Like splitpin says +1 , really need to know your model year of your car,and for what it's worth put the highest octane fuel you can find in your car as saving pennies at the pumps can cost you dearly in the long run.