Boost Level

[GazTurboUK]

Hi guys

Got my 98 uk turbo in november and had always been running 7psi (suspected faulty solenoid) so after sourcing 2 solenoids both werent same as mine (d'oh) finally got one from my model .... changed it tonight and now i seem to be getting a better response but only reaching 5 or 6 (sometimes 7psi).

Any ideas what may be causing this? When i changed it i changed the plate with solenoid etc for ease (dunno if this makes a difference).

Cheers

Gaz

[WRX Ben]

Gaz,

I beleive that the UK turbo should run approx 13psi. Not much help to you but there could be another reason why its not producing boost. Possible air leak somewhere.

Ben

[GazTurboUK]

Looked quickly at all the pipework (engine was hot and it was dark) and everything seemed tight and no obvious leaks. Althought on the 2 vacuum lines from the passenger side of inlet one goes to the vta dump valve and other has a bolt at end??? could this be one of the problems?

All mods were done before i got the car so cant say if they were done correctly

[dipsy]

See the tee piece for the pipe work above the turbo the right hand side of the tee piece has a boost restrictor bill in the pipe work .You will see the pipe work bulge a bit were the pill is if its not there you will run less boost

[Big 'D']

In between your turbo and your actuator you have 2 small pipes and a 't' piece connector, in one of the short pipes there should be a restrictor pill (the pipe between the turbo and the 't' piece) if this is not there or has been fitted between the 't' piece and the actuator you will only see wategate pressure of 7-8 psi max, it is not a split pipe, to test and see if your actuator is working you can disconnect the pipe from it, this will give you uncontrolled boost, so be careful only take the boost upto 1.0 bar max if you can otherwise you will hit overboost fuel cut but what this does is prove that your actuator is clamping the wastegate ok. The only other things that would reduce your boost to actuator pressure are a blocked pipe between the 't' piece and the solenoid and between the solenoid and the intake or your solenoid is simply not working, to prove its operation, if you look under the dash on the drivers side you will find a pair of green 2pin connectors if you connect them together and turn your ignition on the solenoid should start to click if it does not try purging it through with some clutch and brake or carb cleaner, if it still fails to click it is goosed and the cause of your problem.

Sorry for the long essay but I think that covers it all.

Cheers Iain

[GazTurboUK]

Cheers Iain, so is it the pipe to actuator i should disconnect to test actuator?

Then look for pill and failing this?? lol

Cheers

Gaz

[Big 'D']

Cheers Iain, so is it the pipe to actuator i should disconnect to test actuator?

Then look for pill and failing this?? lol

Cheers

Gaz

Firstly as Dipsy has also mentioned look for the restrictor pill, it is possible that it is missing or been put back in the wrong pipe ie between the actuator and the turbo (should be between the turbo and the 't' piece)

Ok if you remove the pipe on the actuator you will get uncontrolled boost, this allows us to prove 2 things, if you get more than 7-8psi (back off the accelerator @ 1.0bar max, the boost will also be quicker than normal so be ready) your turbo is physically ok and your actuator spring is clamping wastegate ok. To further prove the actuator spring you can connect a pipe directly between the turbo and the actuator and you should see 7-8 psi max.

Once you have proven the pill is there and your turbo and actuator are ok, connect the pipes back how they should be and turn to the solenoid, like I mentioned before under the dash on the drivers side there should be a piar of green 2 pin connectors if you connect these together and switch the ignition on you should hear the solenoid tick (even if it does click give it a good clean + associated pipes) if it fails to tick it your problem ( the solenoid fail in a closed position which diverts all the servo pressure from your turbo to the wastegate actuator which will open it @ 7-8psi) if it is ticking (blow through it just to confirm it is operating you will feel the pulses of air as it opens and closes) then look for a blocked pipe, beyond this mate there is no other physical failure for you to check.

Cheers Iain

[GazTurboUK]

Nice one mate cheers

[GazTurboUK]

Cheers Iain, appears my actuator is the problem.

Now for next question i have a spare turbo with no play in shaft/actuator seems solid, should i just swap the actuator or wait and swap full unit? Currently the actuator on the car does seem to vibrate a lot and not sure if would have the same with other actuator?

Cheers

Gaz

[ciaranrb5]

You could just try swapping the actuator quicker than swapping the turbo.

[Big 'D']

You could just try swapping the actuator quicker than swapping the turbo.

Just one thing though, besides the rattling how else have you come to the conclusion that its the actuator at fault? Is it opening to early ie before 7psi when a pipe is connected directly between the turbo and the actuator? It is easier to swap the actuator over mate, if you have access to the actuator arm on the turbo that is fitted to the car (is the heat shield removed), apart from it being loose if you pull on it does the spring feel as strong as the spare one you have, if so you could try and adjust the arm in a bit to take up the slack and try that, when/if you adjust the arm should clamp the wastegate arm closed (just and no more).

Cheers Iain

[GazTurboUK]

Infact i read that wrong oops lol

When disconnected from actuator its boosting over 7psi no probs, pill is there (feels to be) but arm does feel loose (spare turbo is solid no play at all)

[Big 'D']

Infact i read that wrong oops lol

When disconnected from actuator its boosting over 7psi no probs, pill is there (feels to be) but arm does feel loose (spare turbo is solid no play at all)

Out of interest can you try and get a pipe to fit/connect between the actuator and the turbo and see what pressure you get then.

Have you tried the function check and cleaning of the solenoid yet mate ?

Let me know how that goes, so far it seems everything is ok ie turbo, wastegate and restrictor.

Cheers Iain

[GazTurboUK]

thought it was indicating the actuator at fault so stopped there lol, will check the solenoid etc just now

[Big 'D']

thought it was indicating the actuator at fault so stopped there lol, will check the solenoid etc just now

If you can, connect a pipe between your actuator and turbo and let me know the max pressure you get

It is possible that if your wastegate linkage has worn allowing your wastegate to sit open slightly this will have an effect on your max boost so it would be worth checking just to eliminate it as a cause, you should see 7 to 8 psi if not then shorten your wastegate/actuator linkage a 1/2 turn at a time until you get at least 7 psi.

Cheers Iain

[GazTurboUK]

Couldnt find a pipe i could connect between actuator and turbo.

Check cycle and its clicking away nice and fast, quite loud too.

Spare actuator fitted, no more rattling plugged back in and 7psi again

[Big 'D']

Couldnt find a pipe i could connect between actuator and turbo.

Check cycle and its clicking away nice and fast, quite loud too.

Spare actuator fitted, no more rattling plugged back in and 7psi again

Ok if not the

Actuator

Turbo

Restrictor Pill

Solenoid

It must be a blocked pipe, between the 't' piece - solenoid and intake pipe. Or a signal fault with the duty cycle of the solenoid (but I am certain that would throw up a check engine light).

Cheers Iain