jims13 6 Posted March 29, 2008 Report Share Posted March 29, 2008 right, as some of you may no , my mates vr was overfuelling all the way to the ring and back...on tickover it chuckjs out neat fuel...we have changeD the mf and checked and double checke d the wiring and coilpack..weve even swapped them for mine..what else can it be??? it sounds very rough and the plugs are black...like no spark or too much fuelidea's pleasejim Link to post Share on other sites
Devildub_06 0 Posted March 30, 2008 Report Share Posted March 30, 2008 Not sure how clever the ECU's on these are but on some other cars when the lambda sensor fails, closed loop fuelling reverts to a safe fuel map which is purposefully rich to protect the engine, almost like a "get you home mode". If you have a known good one to swap it out with, i'd start there. Link to post Share on other sites
thegoth 5 Posted March 30, 2008 Report Share Posted March 30, 2008 is the maf still showing the open circuit / short to earth error? Link to post Share on other sites
UnitedMotorsport 55 Posted March 30, 2008 Report Share Posted March 30, 2008 If it is OBD1 and the lambda probe signal isnt plausible, the sensor will be ignored and the ecu will add full fuel trim (+25%).If its OBD2 and the sensor signal isnt plausible, the sensor gets ignored, and the ECU runs open loop fuel table, ie no fuel trims are added. Link to post Share on other sites
jims13 6 Posted March 30, 2008 Author Report Share Posted March 30, 2008 tried unplugging the lambda , but no joy..the fuelling probs seem to be at low revs, as it still runs and pulss fine higher up.im gonna chuck thge laptop on it again , and see if the earth/signal fault is still there, but the plug has been checked and double checked and rewired twice.it all started after a track day, and after the car was stopped (hot)we id orig find a broken/snapped afm wire on the plug..so we have swapped the afm for a good one, replaced the plugs and leads, and tested it with a good coilpack, but still the fault remainswould a dodgy ecu relay cause this problem...or shall i dig out the multi meter and start taking volatges etc. Link to post Share on other sites
Devildub_06 0 Posted March 31, 2008 Report Share Posted March 31, 2008 Does this only happen when the engine's warm warm, or at all temp conditions? Link to post Share on other sites
Jimbo-VR6 0 Posted March 31, 2008 Report Share Posted March 31, 2008 All temp conditions Link to post Share on other sites
Devildub_06 0 Posted March 31, 2008 Report Share Posted March 31, 2008 Best to see if that earth fault still exists first, but my thinking would be that if it was a severe MAF prob, it would just run terribly all the way through if at all. My second thought if it's even crap from cold through to warm is that air maybe entering after the MAF which is being picked up by the lambda which in turn is chucked a shed load of fuel in to compensate. Did you originally reset the ECU after repairing the MAF connector? it maybe that adaptions have picked up some bad habits which it can't shake. Always worth doing the easy stuff first! Link to post Share on other sites
jims13 6 Posted April 1, 2008 Author Report Share Posted April 1, 2008 gonna reset the cu tonight and clear any fua;lt codes...then if that dont work im gonna find the pin outs for the ecu , and check each one for dry joints etc.. Link to post Share on other sites
craggsy 91 Posted April 1, 2008 Report Share Posted April 1, 2008 bloody VWs so unreliable Link to post Share on other sites
jims13 6 Posted April 2, 2008 Author Report Share Posted April 2, 2008 right had the car back on the computer, its still showing the maf open /short circuit error.can anyone supply me with a list of the air flow meter pinouts /colours/voltages and the ecu pinouts..we need to have the car fixed by friday...pm me or email me direct with any wiring diagrams you have.does anyone also no if the maf wiring, goes to the fuse box/relay orr straight to the ecu, if its the later is it possible that the orig wiring fault has spiked the ecu? if so is there a easy way to tell.thx jim Link to post Share on other sites
jims13 6 Posted April 3, 2008 Author Report Share Posted April 3, 2008 guys can anyone help?? Link to post Share on other sites
Devildub_06 0 Posted April 7, 2008 Report Share Posted April 7, 2008 Can't say for 100% and sorry for the late reply but as a sensor it should be directly onto the ECU wiring loom, and should also be colour coded. As a basic wiring check do the continuity on the wires that you can identify and check any to earth. If all checks out ok, chances are a voltage spike has probably affected that portion of the ECU. Link to post Share on other sites
jims13 6 Posted April 7, 2008 Author Report Share Posted April 7, 2008 ah, well since my last post..aftera ecu reset we managed tpo get it running, then wheni t gets hot , it wont start without a bit of throttle, so we changed the throttle body and tryed again. but no difference, i then pulled the ecu relay and cleaned it, it now starts when hot.!!so we are gonna replace the ecu relay, and go from there.it only seems to be a problem when the car has been run, so heat build up is affecting a part, so to that end the ecu relay is a possability, also when we popped the cover off the pcbon the back was corroded. Link to post Share on other sites
thegoth 5 Posted April 7, 2008 Report Share Posted April 7, 2008 those damn ecu relays Link to post Share on other sites
jims13 6 Posted April 7, 2008 Author Report Share Posted April 7, 2008 tell me about it, jim's been using the car today, and he said it now starts from hot , but idels slighty high even when warm, but a new ecu relay is on order from vw.. all ready for our trackday on saturday Link to post Share on other sites
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