Could this be the mass air sensor?

Question

I'm still new to this GM / Saab TiD engine, but yesterday I was feeling changes in engine behaviour (output) under acceleration. Some times I have plenty of acceleration, sometimes I have next to no acceleration :) and it was varying. This morning it was find...

It feels just like a petrol turbocharged donk when the ECU shuts down the boost pressure because it was getting too high...

I'm thinking an intermittent problem with the mass air sensor, a DTi thing on UK Vauxhalls and given the TiD's origins, sounds plausable. Is there anything else it might be? A collapsed hose somewhere? Crud in the air filter?

Tim.. · Accepted Answer

Unplug the AMM and go for a drive. If its now smooth, albeit down on power,but consistent, then yes the issue is 95% with the AMM.Tim..

Moray Cuthill · Answer

Also check for any split vacuum hoses, on the engine management piping side. It's quite common for the rubber bits that link up all the plastic pipes/solenoids/actuatos to split, and the plastic pipe to chaf through if not secured properly. Any leaks in the vacuum system usually result in the turbo wastegate not shutting properly (it's vacuum operated via a solenoid valve), and a corresponding lack in power.

DervMan · Answer

AMM? *blushes*

John Greystrong · Answer

Air mass meter, mass air sensor, etc.John

Moray Cuthill · Answer

I just had a thought about that technique. On the GM engine, it should cause the engine to go into limp home mode, so it'll be very flat and only rev to about 2500rpm (and on a Saab, it'll cause the engine management light to stay on for 6 ignition cycles, IIRC)

Could this be the mass air sensor?

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