MFA mpg weirdness and rough running - Coincidence?

[Stirring Moose]

Hi everybody. First up sorry I've not been around Golf-land much recently. Have had some terribly tedious "unemployment" issues to deal with  Anyway, back in business now and dear 'Valver, doubtless smelling the fresh money, has gone wrong. Went to start it up for the first time in a while and it's running rougher than hell, so bad I just shut it down, didn't even want to wait for it to warm up. Just before I put the car away, it was running fine and passed an MOT with a nigh on perfect set of emissions figures. Only odd thing I noticed was that the MFA mpg readout was very optimistic and not very stable. Have done a search for this and have seen people refer to a temp sensor failing and sending the MFA a bit nuts. Wonder if this has occured and is now causing the running prob as well? Any thoughts on this or any other suggestions much appreciated.

S.M.

[harlemex]

perhaps you should start it up again and let it run. I think your ecu needs to re learn its stuff, if ya get me. 

[Stirring Moose]

Interesting, hadn't thought of that one. She's been laid up for longish periods before though and never complained at being woken up. Also, it's smelling quite fuelly and I'm a bit nervous of blowing the cat full of unburned fuel and wrecking the thing.

S.M.

[harlemex]

should be okay while engine is still cold, it will blow it through. 

[Wayne]

Let it warm up again, if still not right then try a new temp sender.

[Stirring Moose]

Thanks Wayne. Afraid warming up now isn't an option though - she is now having a complete tantrum and refusing to start at all!

S.M.

[VW BUSH]

You checked for a spark? not unknown for ignition module or leads to break down if left standing

[Stirring Moose]

Hmm, interesting. Leads should be ok as they are pretty new. By ignition module do you mean the coil pack? Replaced that about five years ago so it's still young-ish and I don't recall any rough running prior to the failure of the last one. However, I firmly believe coils are weird and will go wrong how they like when they like so it's not out of the question.

S.M.

[VW BUSH]

5 Years is old for coil pack, check for spark and rule it out
Relays might be worth a check too

[Stirring Moose]

Update: I ran out of time and facilities so Golfy has departed on a trailer to be tended by Them Wot Know. Unfortunately she's leading them a fair dance too. Apparently spark is fine but the motor is epically overfuelling for reason or reasons currently unknown.

S.M.