mrbeige 0 Posted May 1, 2010 Report Share Posted May 1, 2010 It seems our OBD2 VR is suffering from a rather bad misfire. It seems to be evident at idle and part throttle, but goes away under WOT. I've checked for DTCs with VAG-COM but only have one for a 02 sensor having no signal (00525 O2 Sensor). I was expecting at least to see a problem with the coilpack.I've taken the top plastic covers off that sits over the Coilpack and had a look for any obvious cracking on the top and sides, but nothing obvious, but I would expect the misfire to be there under heavy load/WOT if it were a cracked coilpack and indeed to have the MIL illuminated on the dash.Would a faulty 02 sensor really cause it to misfire? I would think it would just not use closed loop fuelling??Help ;( Link to post Share on other sites
legvw 0 Posted May 1, 2010 Report Share Posted May 1, 2010 It could cause a missfire if its over fueling, wetting the plugs, causing a weak spark. Link to post Share on other sites
The Monk 50 Posted May 1, 2010 Report Share Posted May 1, 2010 It could cause a missfire if its over fueling' date=' wetting the plugs, causing a weak spark.[/quote']Paul, you diagnosed my issue without me posting it I agree with paul buddy. Link to post Share on other sites
mrbeige 0 Posted May 3, 2010 Author Report Share Posted May 3, 2010 I did wonder if the signal from the 02 sensor wasn't good, it would'nt run in closed loop fuelling (idle/part throttle). The problem seems to go away at WOT.I've whipped the spark plugs out yesterday. Cyl 1,2 and 6 had a white deposit on the electrodes and were a little wet (ish), the other 3 looked ok.Found the cause of the DTC though...just need a new female terminal now....oh and a pin extraction tool... Link to post Share on other sites
craggsy 91 Posted May 3, 2010 Report Share Posted May 3, 2010 Lambda doesn't work at WOT anyway. But try a hair clip or paper clip Link to post Share on other sites
RAPgolfvr6182 2 Posted May 3, 2010 Report Share Posted May 3, 2010 if plugs are white means there running to hot Link to post Share on other sites
mrbeige 0 Posted May 3, 2010 Author Report Share Posted May 3, 2010 if plugs are white means there running to hotHot could mean lean?? Link to post Share on other sites
legvw 0 Posted May 3, 2010 Report Share Posted May 3, 2010 if plugs are white means there running to hotHot could mean lean??Yes, fuel is used to also cool the engine/plugs. Not enough and yes white plugs. Link to post Share on other sites
mrbeige 0 Posted May 5, 2010 Author Report Share Posted May 5, 2010 Some terminals and a terminal extraction tool have arrived today, so hopefully we'll be rolling again later Link to post Share on other sites
mrbeige 0 Posted May 6, 2010 Author Report Share Posted May 6, 2010 Tis all fixed! Misfire has gone away. Dubiously short length on the wiring now though, so will fix that when the engine comes out in the next month or so Link to post Share on other sites
RAPgolfvr6182 2 Posted May 6, 2010 Report Share Posted May 6, 2010 what was the problem with it? Link to post Share on other sites
mrbeige 0 Posted May 6, 2010 Author Report Share Posted May 6, 2010 Broken wiring for the O2 sensor, causing over/under fueling and misfire at idle and part throttle. Link to post Share on other sites
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