slight backfire and stalling. Intermittent??

[windydubber]

Hi,
Went away again in the van at the weekend. Been running fine but on the way home it started backfiring a little when off the power. Then it began to stall when off the accelerator. It did the stalling thing before but stopped as fast as it started. Anyway, it did this for about fifteen miles then cleared up and ran fine?? Very strange! Any ideas would be appreciated.

Its a 1981 2.0l air cooled petrol.
Cheers

[mike9009]

Hi

These symptoms could be a result of many different failures, so it is probably good to take a systematic approach. First check the fuelling system (filters, pump, carb cleanliness at top level) once happy with that move onto the electrics... (I always associate backfiring with electrical issues..... though, this is not strictly correct. But I associate it with fuel not being ignited in the cylinder, but in the exhaust....)

I had similar symptoms, and the stalling became more and more frequent. Eventually it would only run for a mile or so before dying. If I left it for ten minutes it would start again and run for another mile. I could get over it temporarily by revving it at any opportunity I came off the power. Eventually got it down to the ignition amplifier.

Mike

[windydubber]

Cheers Mike. I have a few days off this weekend so will try and eliminate as much as possible!
Cheers!
Nik

[CovKid]

Ignition leads that are breaking down can sometimes only show up once they start to get warm. Certainly had those symptoms before and new leads cured it, but as said, could be a few things.

[what2do]

Worth checking the vac/advance unit???

[windydubber]

Covkid, do you mean the HT leads? and should I look at other ones? Battery leads etc?

[CovKid]

Yes HT leads. Sometimes you can see the problem in pitch black (ie arcing) at other times you can't. The metal shrouds can be troublesome I gather. I don't want to send you down a path that isn't correct in your case, but put it this way, if the leads are old, they'd be on my list.

[windydubber]

Who would you get the leads from? Brickwerks, VW Heritage, or somewhere else?

[mike9009]

I have used brickwerks in the past and been happy with their service. (not bought HT leads from them though, but I think most of the products they sell are of decent quality and come recommended)


Mike

[CovKid]

The ones I got from GSF were also good but I'd check them in the car park and make sure they reach before you leave.