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Model specific boards => Golf mk3 => Topic started by: Stirring Moose on 17 November 2011, 20:03

Title: MFA mpg weirdness and rough running - Coincidence?
Post by: Stirring Moose on 17 November 2011, 20:03
Hi everybody. First up sorry I've not been around Golf-land much recently. Have had some terribly tedious "unemployment" issues to deal with  :sad: 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.
Title: Re: MFA mpg weirdness and rough running - Coincidence?
Post by: harlemex on 17 November 2011, 21:21
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.  :smiley:
Title: Re: MFA mpg weirdness and rough running - Coincidence?
Post by: Stirring Moose on 17 November 2011, 21:46
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.
Title: Re: MFA mpg weirdness and rough running - Coincidence?
Post by: harlemex on 17 November 2011, 21:54
should be okay while engine is still cold, it will blow it through.  :cool:
Title: Re: MFA mpg weirdness and rough running - Coincidence?
Post by: Wayne on 18 November 2011, 00:01
Let it warm up again, if still not right then try a new temp sender.
Title: Re: MFA mpg weirdness and rough running - Coincidence?
Post by: Stirring Moose on 18 November 2011, 16:42
Thanks Wayne. Afraid warming up now isn't an option though - she is now having a complete tantrum and refusing to start at all! :angry:

S.M.
Title: Re: MFA mpg weirdness and rough running - Coincidence?
Post by: VW BUSH on 18 November 2011, 16:47
You checked for a spark? not unknown for ignition module or leads to break down if left standing
Title: Re: MFA mpg weirdness and rough running - Coincidence?
Post by: Stirring Moose on 18 November 2011, 17:09
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.
Title: Re: MFA mpg weirdness and rough running - Coincidence?
Post by: VW BUSH on 18 November 2011, 17:19
5 Years is old for coil pack, check for spark and rule it out :smiley:
Relays might be worth a check too
Title: Re: MFA mpg weirdness and rough running - Coincidence?
Post by: Stirring Moose on 23 November 2011, 17:44
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.