ABY intermittant cut out/stall....

[JamesHarrold]

Sorry, forgot to say...Thanks Andy, for your original diagnosis

James

[JamesHarrold]

Jumped the lights a bit there....! Could it be cam sensor if it only stalls when hot, as previous page suggests?

James

[S2central.net]

Cam sensor fails do seem to be most common at extremes of temperature... Have your ruled out 2 x POS units already ?

[JamesHarrold]

Hi Paul....Thanks for the reply....But POS were both changed a few months ago.
Doesnt go down on 4 cyl just cuts out completely....Why would it fire and start for a second before cutting out completely...? Does engine need to be running for ecu to detect a fault?

James

[Fat Audi 80]

Paul,

Have you not stated in some other diagnosis posts that the Camshaft position sensor is only used to start the car and then the car can run without by using the crank position sensor? Or have I got it the wrong way round?

@ James, have you pulled the fault codes again, from what you are describing, could you also not be seeing a huge amount of unmetered air going into the intake system causing this fault? It maybe that one you pipes is badly split.

HTH

Cheers.

Steve.

[JamesHarrold]

Hi Steve....


I have reset the ECU and the only code I am getting is 2224 (maximum charge air exceeded)
But having not even turned a wheel, let alone produced any boost - how can this be?
Also pressure checked the whole system and no leaks that I can see/hear...

Does the cam sensor not work when the engine is running...guess it may be the crank sensor then?

Cheers
James

[S2central.net]

Cam sensor is critical for engine start, but engine should run after cam sensor disconnected - it uses the two crank sensors as substitutes and retards timing a bit for safety.

You might have a dicky crank sensor or RPM sensor. Dunno if they are more likely to fail with heat.

[S2central.net]

Have you checked that all ground wires are good... two on the inlet manifold and one at rear of head ?

[JamesHarrold]

Hi Paul...Yep, checked most of the ground wires that I can see - All look good to me.
Are you saying that it is unlikely to be the cam sensor and more likely the crank sensor? If so, which one of the two near the flywheel is it...?

Cheers Paul

James

[S2central.net]

Check them both... maybe swap out with someone else - they are expensive. There is a simple resistance test you can do, but you really need a scope to see the signals properly. Could just be crap connections... The sensors are actually identical but color coded the connector bay on the bulkhead so they don't easily get mixed up.

[JamesHarrold]

Thanks for the info....will check wiring, but dont think there is anyone round here I could swop with....
Read on here that someone had a similar problem, which seemed heat related. Car wouldnt start/run when hot. Think that turned out to be the cam sensor but cant find the thread
Are you saying i should rule it out then Paul? As it is only used when cranking?

Latest test is to start the car up from cold and leave it running for about 20 mins....starts fine but gradually gets worse and stalls when up to temp. Does every time, which i guess is a good thing for replicating the problem. Are there anymore checks I can be doing as/when it stalls?

Cheers
James

[S2central.net]

Do you have VAGCOM - I'd like to see what Group 0 is showing from cold start up to point where it stumbles and dies. Bit of an odd one.

[JamesHarrold]

No VAGCOM unfortuanately...What is Group 0 Paul?
James

[S2central.net]

Its a VAGCOM thing... its one grouping of data from inside the ECU... There's other useful groups too.

[JamesHarrold]

Is it worth taking it to the Bosch dude in Norwich for a plug in...?
See what he thinks?
James