Lexia parameters recording

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myglaren
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Re: Lexia parameters recording

Post by myglaren »

I've used carburettor cleaner on the MAF. Made no difference to it either way.
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Re: Lexia parameters recording

Post by MikeT »

I have a confession to make. I think I might have made matters worse.

I removed the turbo-maf ducting and gave that a good solvent wash as it oily. I gently sprayed the air-side of the MAF (but didn't remove it to do a better job). The solvent evaporates fast so thought I was safe to start the car some time after refitting.

On starting the rpms rose very briefly (to about 2krpm) with a horrid ratcheting sound (like something interfering with a fast-rotating part) - I'm wondering if something got dislodged and was ingested by the turbo or the shaft moved beyond it's normal range and allowed the impellers to impact the housing?

Almost as soon as it occured, the rpms settled back to idle and nothing untoward has been noticed since.

Additonally, I took a drive last evening to record turbo-related parameters. I can't tell if it's normal lag or a real problem but the actual measured turbo pressure is often seen lagging (by up to 300mbar) to the turbo pressure setting. I say lagging but there's times when pressure setting is higher for several seconds that the actual measured pressure never reaches.


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Re: Lexia parameters recording

Post by RichardW »

That looks pretty suspect to me Mike - either the turbo is goosed, or the pressure sensor is! Try pushing down the vane actuator on the front of the turbo, then letting go, it should spring straight back up. If it doesn't then the vanes are gummed up.
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Re: Lexia parameters recording

Post by MikeT »

The actuator rod plunges down and rises back up nice and smoothly. But I guess that says nothing for the state of the actual diaphragm and vaccum supply, nor the other parts of the turbo. The fact it can make over 2000mbar most times it's asked (if the sensor is accurate) makes me wonder if it's a transient problem, like the vanes sticking or a vacuum leak.
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