V6 AFM Failure

[techbotics]

Hello Gents

My S has been running very badly recently.. the local garage have declared the AFM's suspect and reccommended replacement of both @ £250 each...

I have not seen name occurances of these failing of the forum and was interested in your thoughts..

Sympotms are the car starts well and then fails to rev beyons say 2000 RPM while underload.. above that speed the engine missfires like crazy and pops and cracks through the exhaust (once its hot)

this feels like it did a while ago before we replaced the fuel pump.. also it seems to have been overfueling like crazy recently.

Has anyone ever had to replace an AFM..?

Thanks

Damian

[Gerald-TVR]

I've got a couple you can try off the last S I dismantled. Drop me a PM if interested

[Griffinr]

I wouldn’t immediately jump to the conclusion of an AFM fault but they can get very dirty especially if the breather pipe is still attached. If you take the filter off you can see how dirty they are and clean them with carb cleaner if necessary. Be careful of the delicate sensor wire inside though.
If the performance has dropped off suddenly I’d start with checking and cleaning electrical connections
Rob.

[phillpot]

wasn't there a thread some time ago about openning these up to clean the wiper and track inside?

they're "sealed for life" but the black lids can be removed, I believe, if you're very careful and then re-sealed.

Also have a pair of "unknown" second hand if any help (Birmingham area)


Thinking about it, sounds a bit like how mine ran when one of the tubes between the AFU's and engine fell of?

Are yours in good order, no splits or not properly fitted at one end or other?

Edited by phillpot on Tuesday 19th June 22:09

[techbotics]

Thanks for the replies gents I will check hoses etc..

also thanks for part offers will see how I get on and let you know.

cheers D

[Ceejay73]

Just my 2 penneth but popping/ banging through exhaust, mis-firing as revs rise, unburnt fuel and all getting worse as it gets warmer sound more like an ignition fault to me. Do you have access to an oscilloscope or know anyone who does? If so I would be checking the output waveform from the ignition amp module on dizzy.

Cheers,
Carl.

[techbotics]

the ignition module was on the list of suspects.. One of the AFM's is obviously broken though.. So will require replacement.

cheers D S3