Boost Issues

[BabyBoy]

Hi Guys,

I finally have my vr4 up and running and the new engine is in it, however, im still having issues as when im driving fast the car pauses for a sec to think about boosting and then boosts and also, after driving lthe car like the way its supposed to, and stop at the lights the engine starts shaking and dropping revs almost switchin off any one has any ideas what could be wrong?

all ideas would be appretiated.

[Nutter_John]

Waht plugs have you got in there , the hestitation could be the plugs , as for the other not too sure

[Subaru ETA]

air leak? that would cause it to hesitate and to idle like crap

[BabyBoy]

Waht plugs have you got in there , the hestitation could be the plugs , as for the other not too sure

Thanks bro, I have ngk's on the car but ill be changing them on the weekend as im going to fully service the car.

[BabyBoy]

air leak? that would cause it to hesitate and to idle like crap

Yeah I thought it could be an air leak, but i have no idea from where? Looks like thats going to be a weekend job.

[Subaru ETA]

intake manifold? turbo piping?

[bradc]

also check if the bov is leaking badly

[BabyBoy]

also check if the bov is leaking badly

ill check the intake piping , but bradc you could be right cos the car is hissing and seems to be dumping air constantly when im boosting. thanks guys will have to check this all at the weekend.

[bradc]

It is a common problem with the stock ones

[Wodjno]

ill check the intake piping , but bradc you could be right cos the car is hissing and seems to be dumping air constantly when im boosting. thanks guys will have to check this all at the weekend.

Deffo sounds like it's leaking somewhere ! Check to see if the vac pipe is connected to the DV..

[BabyBoy]

Deffo sounds like it's leaking somewhere ! Check to see if the vac pipe is connected to the DV..

will do that bro, i thought there was also an issue with the valves at the intake cos they kept on rattling.

[BabyBoy]

ok guys i there is no loose pipes, all pipes are connected tightly and the vacum pipe is connected to the dv. so i have no idea where the air is leakin from plus ill change the spark plugs and see if it makes a difference.

[pezza]

If you are hearing air escape under acceleration is could be that odd shaped squashed flat plastic return pipe from the dump valve. I had to replace mine shortly after buying my leggie.

Are you using the original plugs from the engine?

If you dont thrash the car, and then come to a stop does it run ok? Are you driving with the aircon on?

Cheers

[TAR]

Could be a sticky idle stepper motor causing the poor idle.

[BabyBoy]

If you are hearing air escape under acceleration is could be that odd shaped squashed flat plastic return pipe from the dump valve. I had to replace mine shortly after buying my leggie.

Are you using the original plugs from the engine?

If you dont thrash the car, and then come to a stop does it run ok? Are you driving with the aircon on?

Cheers

Hi derek,

im using the plugs you sent with the engine as the fool of the mechanic i have did not change them. the air con is on all the time. And the dv plastix seems ok. the air seems to be leaking from the drivers side.

If i dont thrash the car and come to a stop the car runs ok.

i think i might have to change one of the tappets as well.

cheers

[The Vee]

If you can hear it drivers side, check the pipes are connected to the valve for the PAS which is located in front of the front cam timing cover above the drive belts.

[pezza]

Hi derek,

im using the plugs you sent with the engine as the fool of the mechanic i have did not change them. the air con is on all the time. And the dv plastix seems ok. the air seems to be leaking from the drivers side.

If i dont thrash the car and come to a stop the car runs ok.

i think i might have to change one of the tappets as well.

cheers

Hmm those plugs probably been on for a year to 18months I imagine... but best to check the condition I guess.

Try the spirited drive with the aircon off. There have been a few issues reported here fairly recently regarding driving the car hard and then the car almost stalling and dying afterwards when coming to a halt. A few people experienced this also just exiting a motorway and coming to a halt at the end of slip road or roundabout etc. Various faults were down to Aircon loading causing the revs to drop relating to idle stepper motor, BOV/DV issues, alternator, and sometimes MAF.

In fact I would check idle stepper motor as I know I had mine cleaned out a few times. Do you still have the one from your old engine?

Not sure about the air leak, do you hear it at idle or only under acceleration? How loud is it? Checking it when on Rolling road or under light loading when up on ramp could help.

And tappets wise, shouldn't be hearing that at all as they were done within last 15k miles. What oil is in there now?


Cheers

Derek