Right, I rarely post technical questions, but these days I'm finding it hard to find time to do loads of trouble shooting on the Polo, but as stated above I'm suffering a missfire under load(sometime even the lightest of loads, ie pulling off on a flat road). It normally developes after a prolonged wet weather drive(lots of spray/puddles etc) and often as this morning after driving home in the wet last night, it was a pig this morning. I'm convinced its a spark issue, I've had coil off and cleaned up all the contacts and check resistances(as per Haynes :-X) and all appears good, plugs appear as they should do, dizzy and cap new last year, leads are 8mm silcon magnacor. Never had any problems in the wet last summer and particulay on our Peaks run(very wet) it was fine(fully loaded up too). So I'm open to suggestions, any old favourites I've failed to check on??????????
it's going to be water getting into the ignition system somewhere. Perhaps a slight crack in the dizzy cap? Spraying in some WD40 can help to get rid of water that's in there.
To be honest I don't rate those Magnecor leads, they have been known to cause issues in the past on g40s. I swear by the german made ones from GSF for about £30, even very high power g40s running aquamist, silly boost levels and nitrous don't have spark problems with those leads.
Aye- as Paul says the magnecor ones have been known to cause problems in the past.
How old are your plugs?
Quote from: Yoof on March 11, 2009, 09:46:05 AM
Aye- as Paul says the magnecor ones have been known to cause problems in the past.
How old are your plugs?
Good question that, I remembered I fitted the original Bosch plug's back on it after breaking one of my NGK's on the last rebuild back last year, and too be honest they are as old as the hill's. Gonna pick up some new plugs this week, I did check resistance on them and all seemed fine(the same that is) in cold state as were the leads, so perhaps it is an aging plug issue. I know the NGK's I where running where fine before(though I 'm also aware some of us swear by the WPD0's).
Will change plugs then look at leads, cheers boy's......
Quick update,
Changed plugs, no difference.... changed leads and definate loss of miss-fire in all senarios, completed first wet weather run on new leads this eve and all is sweet.
Noted a rather tired looking earth strap between G/box and coil, so think I'll make one up ready for the next spanner session.