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[arthill]

 Still having problems with car, lossing power under load replaced cam sensor but left with fuel trim (lean ) as the only fault left, mechanic done live diagnostic test while fault was present on lambda sensors, said sensor after cat showed fluctuation where it should be constant. However after stopping and restarting engine fault code  was not present and lambda sensor was reacting as it should ie. constant, he suspects MAF , could this be the answer? any thoughts thanks.  :-/

John

[cem_devecioglu]

Mass Air Flowmeters dont fail easily..

Only loose little performance with time as its a chemical surface..

In your case the reason also can be a combination..

Whats the mileage..

If you rev it does it have any limitation..

Didi you service normal items including air filter,fuel filter,sparks,oil etc

[arthill]

car recently had fuel filter, spark plugs, oil change, no limitation on revs except when this intermittant fault occurs, then it is as if something stopping accelerater and has to be forced to get response,
but stop car switch off and back on and car is fine again

  John

[Marks DTM Calib]

Hmmmm....it realy needs a good diagnostic tool to look at the live data to confirm.

[arthill]

Going back in to garage today, had emissions tested at mechanics suggestion, read out showed the lambda part was high, but h is not convinced it is lambda sensor, could those symptoms be caused by MAF sensor,

John

[Marks DTM Calib]

Going back in to garage today, had emissions tested at mechanics suggestion, read out showed the lambda part was high, but h is not convinced it is lambda sensor, could those symptoms be caused by MAF sensor,

John

In my view no.....as the lambda would correct the mixture to compensate so I suspect the emissions readings are a red herring.

The lack of acceleration and sudden low power could be the MAF but again, it needs checking with live values.

A proper diag session should monitor the airflow with respect to throttle changes etc....I would also be looking at the coolant temp readings as well.

[arthill]

Thanks Mark

John

[arthill]

Hi

Had car in garage today to check MAF. voltage checked at idle voltage read .6 mechanic said reading expected was 1.1,   when revved reading was 3.2 as expected.  after disconnectng and re-connecting Maf MIL went out , can I assume therefore that this is part of my problem.

  John

[Marks DTM Calib]

Hi

Had car in garage today to check MAF. voltage checked at idle voltage read .6 mechanic said reading expected was 1.1,   when revved reading was 3.2 as expected.  after disconnectng and re-connecting Maf MIL went out , can I assume therefore that this is part of my problem.

  John

No you cant.....it could read 0.6 at idle if there is an airleak...hence why he should have done further tests and actuator tests.

The fact that it is tracking throttle sudgest the opposite and that it is good.

The fact that disconnecting and re-connecting MAF tends to sudgest more of a wiring fault or poor connection....but then again it could be a red herring.

[arthill]

Thanks Mark

Going back in next week, will be discussing your comments with him, and report back here. thanks again.

  John

[cem_devecioglu]

Just an idea check the injectors connector socket behind the plenum..

Take the socket and wash with wd40 or with a rust solver spray and

plug it back..Mine did something similiar and become a headache

once..

And a cheap advice ..Change the o-rings around the inlet manifold..If

they are old they become tiny and leak air..

May be these will not solve your problem but will prevent extras in the

future..

[arthill]

 Reporting back as I said, back to garage on wednesday, fitted new maf and all fault codes disappeared, took car for run and it seemed fine, I've been working all week so car had been parked until this afternoon, although lying that time and the cold weather it started straight away with immediate response from accelerator drove to the places I had problems before puting car under load and everything was fine and so far there has been no problems. Hopefuly this is the end of a long saga. Thanks again for all your help.

 John

ps. bought maf from partsdome on ebay £32.95

[Marks DTM Calib]

Reporting back as I said, back to garage on wednesday, fitted new maf and all fault codes disappeared, took car for run and it seemed fine, I've been working all week so car had been parked until this afternoon, although lying that time and the cold weather it started straight away with immediate response from accelerator drove to the places I had problems before puting car under load and everything was fine and so far there has been no problems. Hopefuly this is the end of a long saga. Thanks again for all your help.

 John

ps. bought maf from partsdome on ebay £32.95

Interesting, I have only ever seen MAFs fail on 2.2 petrols and the odd 2.5TD......

[arthill]

mine is 2.2 petrol