1ggte cutting out under boost

[VasH]

If the car starts to build any sort of boost it will cut out if you then back off the accelerator and re-apply it goes again. If you hold your foot down while it cuts out it will cut in again but as soon as it starts to boost it will cut out almost like its missing. Sometimes it will boost properly if you keep holding your foot but seems to miss a few times until then.

[Admiral coFF33]

Cut out as in not boost ( 0 on the gauge) or as in engine stops running as if turned off.

[VasH]

Cut out as in not boost ( 0 on the gauge) or as in engine stops running as if turned off.

when the guage goes above zero and the turbo light on the dash comes on it will cut out feels and sounds like the engine is actually off for a moment but will kick back into life after say 2-3 seconds

[Admiral coFF33]

Well i guess if its cutting spark, and engine is actually turning off and on, Easiest thing to initially try is just a ECU reset. (disconnect negative batt lead for an hour or so)

Does the engine "sound" healthy when off boost ?

[VasH]

Well i guess if its cutting spark, and engine is actually turning off and on, Easiest thing to initially try is just a ECU reset. (disconnect negative batt lead for an hour or so)

Does the engine "sound" healthy when off boost ?

Yea ive reset it a couple of times still happens

[Kedderz]

any codes being thrown by ecu?
checked AFM wiring/plugs?
checked all intercooler piping/listened for air/boost leaks?

[love ke70]

if your leaking a heap of boost it may be reading a heap of air going in, but not getting to the motor, running hell rich and killing itself?

probably not whats happening, but start with the basics like leaks etc

[TheToyman75]

SOunds like Boost cut to me.

Where is your boost GUage connected to ? If its connected atthe plenum chamber you want to temperarily take your reading from the Turbo Scroll and see what boost your turbo is making. If your still making no boost at the turbo's at cut point then I'd e checking the AFM.

[Admiral coFF33]

he said as soon as it goes positive ... as in above 0 on gauge ,

therefore only minor boost will cause it ...

Im starting to think air leak somewhere too ... check all silicon joins ?

[TheToyman75]

he said as soon as it goes positive ... as in above 0 on gauge ,

therefore only minor boost will cause it ...

Im starting to think air leak somewhere too ... check all silicon joins ?

As soon as it goes positive on the guage can easily be boost cut if he has a boost leak - You have to remember that Boost cut is not Boost referenced but triggered by Air flow at the AFM.

Measure the boost at the Turbo - What is it ?
If that checks out of check for a restriction, Ie a failed cat will prevent boost being generated but not limit the intake charge hence causeing premature boost cut

Mind you it could be a million other things too.

The AFM could be poked
The AFM wiring could be poked
It could be losing spark
It may be starving for fuel
It may just not like wednesdays
Perhaps it has the flu or is just Premenstral

All these questions and more have no chance of being answered with such little information provided so far but I can keep guessing

[VasH]

I cant find any leaks anywhere. The car runs perfectly fine as long as its no boosting, sometimes it will boost up and hold fine but this is pretty rare i checked the afm wiring as much as i could it all seems to be ok aswell

Holding my foot down flat it will rev up then boost starts it cuts out for a sec if you still hold your foot it will come back to life and continue on but once boost starts it cuts out again. According to the gauge sometimes it will get to about 5 psi

Another thing i noticed when the engine does cut out during this period u can pump the accelerator and no change to rev's and u can hear any noise from the exhaust.

Maybe my best bet is to take it somewhere to get looked at

EDIT" tried to bring up ecu error codes but it just continuously flashes im guessing that means thats theres no errors?

[Duk]

Check all your spark plugs, better still, replace them.
Same said for ignition leads and distributor cap (does it have 1?). Also check coil(s) for signs of cracking around the high tension plug(s).
Check fuel pressure when the idling, driving normally and when it comes onto boost. It should smothely increase as manifold pressure increases.
Jam an Air/Fuel ratio meter into it if you have access to 1. Even the old flashing LED 1 on the standard oxy sensor will show a lean condition.

[VasH]

Good news found out what the problem was, turns out the fuel pump relay is a bit touchy it was also causing my car to not start at all after replacing the plugs and checking all the wiring taking the dizzy apart i must of bumped it or something cause the car started yesterday and wouldnt start this morning so this arvo out of curiosity i gave it a few taps and car fired up went down the road to test it out and ive got my boost back wooo!

Anyone have a spare relay handy im not sure how long this one is going to last or can you get new ones that will suit?

Thanks everyone for the help and advice