Possible failed wastegate actuator?

Arrrggh! What happened by boost?

My top boost has dropped from 0.8 bar to 0.5 bar and my basic boost has dropped from 0.35 bar to just under 0.2 bar.

My boost curve has altered as well - it used to dip slightly somewhere after

3000 RPM and tail off to about 0.5 bar somewhere around 5000 RPM. Now it tails off dramatically at about 3000 and pretty much basic boost levels thereafter.

I have tested the APC box by upping the F & P pots which does give me a slightly higher boost, so I think we can discount APC box problems. Given that the basic boost has dropped I looked at the wastegate actuator and I'm sure there was more thread there before. Whenever I've adjusted the it before, I've gripped it with a mole grip and then adjusted the nut and end arm. I can only just get my smallest mole grip on now and there's no room to adjust the nut.

Has my actuator failed? The car is going into my garage tomorrow, so if this kind of behaviour fits with a failed actuator, I can hopefully have them replace it.

Your advice would be very much appreciated.

Paul

1989 900 Turbo S
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Reply to
Paul Halliday
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Hmm, dunno, doesn't sound like the actuator. Have you tested it? Disconnect the vac hose which goes to the actuator, and suck/blow. Anything?

Reply to
Grunff

in article snipped-for-privacy@demeter.uk.clara.net, Grunff at snipped-for-privacy@ixxa.com wrote on 12/10/03 4:26 pm:

Which way? Disconnect from the APC solenoid and suck/blow on the pipe attempting to affect the actuator?

What should happen? If air passes then the diaphragm is done? Is there a spring in the stock actuator that could've broken or suddenly gone weak?

Questions, questions. Thanks Grunff.

Paul

Reply to
Paul Halliday

Yes.

Yup.

There is a spring, yes. I've never come across a broken one. But it is possible.

Reply to
Grunff

in article BBAF0BC4.A875% snipped-for-privacy@blueyonder.co.uk, Paul Halliday at snipped-for-privacy@blueyonder.co.uk wrote on 12/10/03 1:46 pm:

My garage, in passing conversation, inform that the actuator has gone soft. They've advised I invest in an uprated actuator. So, who am I to disagree :)

Thanks for the replies.

Paul

Reply to
Paul Halliday

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