my saff was boosting at a 33psi spike, sunday it stopped ,and now peaks at 27psi.... i tried taking the wastegate actuator hose off ,so the wastegate is closed all the time, this should boost way too much...but still only makes 27psi

what do you reckon?

 

stuck wastegate?

boost leak at hose or jub clip?

 

Big air leak most likely pal.

 

the wastegate is free, i checked that as i tried to put another meter of preload on the actuator

must be an air leak somewhere? cant be turbo if it makes 27?

 

seemed poor on fuel today to , must be an air leak...plenum off then!!


thanks guys!

 

If teh wastegate stuck open it would be laggy as hell.

If it stuck closed it would overboost, not underboost.

Air leak or dying turbo it must be. UNLESS, your amal valve is clogged with shit. Worth a check.

 

thanks stu.

even if i take the pipe of the actuator, so the amal etc is disconneted and the wastegate is closed at all times it still peaks at 27 , i hope the plenum is leaking... i tightened it the other day, and three bolts were lose (third time its done it!) so its probably split the seal i expect...

Thanks again!

 

Best of luck pal.

 

Whats your idle doing?

If it is about right, then it is unlikely to be pipe off/split, as this would generally increase the idle speed (think ISCV)

Make sure that all the clips are tight, as I found that in the past when I have had similar problem, it turned out to be one of the jubilee clips on one of the large boost hoses.

Hope this helps

JJ

 

his idle has been all over the place, its an air leak. James its an air leak

 

dump vale diaphram split

 

I had a similar problem a few weeks ago mate
boost drop, bad fuelling and dodgy idle
turned out to be my inlet plenum gasket that was knackered.

 

well, thanks for the replies guys!

i made an adaptor today so i could connect my cylinder leakage tester to the outlet boost hose from the turbo...

connected it all up and tested it at 2 bar.. had a 60% loss

the manifold-plenum gasket (or sealer!) had gone on a stretch about 4 inches long




also getting a very small air leak from around the iscv, do these have one seal or two?

mine only has one? it may be leaking because the valve shut ,and when the throttle is open the iscv opens to, so this may stop it leaking?

 

glad you found the problem told you it was an air leak

 

And they have TWO seals.

 

ahh! where does the second one go then? i have a small one at the bottom.....

thanks guys!

 

im gonna have 65psi when i fix all the leaks