mrbeige 0 Posted July 15, 2008 Report Share Posted July 15, 2008 Well, two days into VR ownership and it failed to start. Called the AA out, and seems like the fuel pump wasn't priming. He took out the fuel pump relay, and also the X-relief relay, and hey-presto it started. Did the same yesterday and I pulled both of those replays out again and re-inserted and it started. The fuel pump relay seems relatively new, could it be an intermittent fault with it? I can't see how it could be the x-relief relay and the starter turns the engine over fine. So, crank sensor maybe? Just seems odd to be intermittent like that.In the meantime, I've ordered a VAG-com lead kit and will check for faults when that gets here....Any suggestions to confirm or deny my thinking much appreciated :-) Link to post Share on other sites
rigs 0 Posted July 15, 2008 Report Share Posted July 15, 2008 Could well be a dodgy pump relay or poor contact in the fusebox Link to post Share on other sites
mrbeige 0 Posted July 18, 2008 Author Report Share Posted July 18, 2008 Quick update:Seems to have been behaving itself, until last night, and we think it only seems to have the problem when the car is warm and is left for about 30mins or so. Removed and reinserted the Fuel pump relay, not effect, did the same with the X-relief, but scratched the contacts inside with my finger nail, reinserted the relay and she started again....weird. Link to post Share on other sites
g60bron 0 Posted July 18, 2008 Report Share Posted July 18, 2008 sound very odd... bit like flipping the coin first... where did you get ur vag com lead from??? Link to post Share on other sites
mrbeige 0 Posted July 18, 2008 Author Report Share Posted July 18, 2008 I've ordered one from Arcadia In Car, an online place. Not arrived yet though Link to post Share on other sites
jws vr6 0 Posted July 30, 2008 Report Share Posted July 30, 2008 Having the same problem with mine, thinking its the crank sensor so going to try one off an old engine i have! Will keep you posted on how it goes. Link to post Share on other sites
mrbeige 0 Posted July 31, 2008 Author Report Share Posted July 31, 2008 That'd be good, cheers. Been talking to a guy at work, and he reckons that crank sensors either work or the don't so, I'm not so sure its the crank sensor on ours.The engine died in traffic yesterday morning, I funked about with the relays a bit, then it started again, 300 yards down the road it did it again, repeated mucking about with the relay and off it went again. Did some testing of the wiring yesterday lunchtime and all seemed fine, good earths on the relay pins, goood continuity on pin 6 from the ECU to the high side of the Fuel Pump relay as well. Removed the fuel pump relay and cleaned the contacts, tested on the bench with a 12v power supply and seems to be functioning fine, just s pity I didn't test it before cleaning the contacts. VAG-com gave several errors, including intermittent on crank sensor, fuel pump relay and all 6 injectors. I think that the injectors is a red herring though. Not so sure about the crank sensor. Took it for a 50minute run last night with VAG-com plugged in a took a log of several of the measuring block, including ECU voltage to make sure that it wasn't that dropping out. All seems as expected.I also checked the plug on the crank sensor for moisture, but it was dry as a bone inside, although the plug wasn't clipped into the plastic holder by the back of the fan, it was just dangling about.Going to the Stealers today to pick up new water pump etc, and will price up a new Fuel Pump relay, but have a bridging wire in the car now so if it does it agaion I can bridge the pins in the Fuel pump relay position on the fuseboard to eliminate that as the cause. Link to post Share on other sites
jws vr6 0 Posted August 2, 2008 Report Share Posted August 2, 2008 Yea mine cuts out aswell, but that only started donig that recently, starting probs been going on for a few months tho.So far ive replaced engine temp sensor and fuel pump relay, and plug leads but also had a slight misfire under load which the new leads cured.A crank sensor has a resistance across it,and resistance is affected by heat, and problem only happens when hot. And if the crank sensors knackered then engine doesnt know its turning so no spark or injection. Deffo worth a try since i have one lying around, got quoted about £80 + vat from dealers tho.Another theorey is lambda sensor knackered causing overfuelling and flooding the engine, but no access to vagcom yet to check codes so not sure. And never had a chance to have a proper look at the car when the faults been happening!Search on here for crank sensor, theres a few with the same fault so fingers crossed! And theres another thread going at the moment with similar prob aswell. Link to post Share on other sites
jws vr6 0 Posted August 2, 2008 Report Share Posted August 2, 2008 Read through thishttp://www.vr6oc.com/e107_plugins/forum/forum_viewtopic.php?117404.postAnd read kevhaywire's post on this onehttp://www.vr6oc.com/e107_plugins/forum/forum_viewtopic.php?83595.0 Link to post Share on other sites
mrbeige 0 Posted August 3, 2008 Author Report Share Posted August 3, 2008 Cheers James. Those threads make interesting reading. I changed the water pump yesterday and had a poke around the engine speeed sensor again whilst I was at it. Did VAG-com first and cleaed two faults - Engine speed sensor and Charcoal Solenoid Valve, disconnected the plug to the solenoid valve (behind the air box) removed the engine speed sensor and the sensing disc was all scored. It looks like someone has used some emery papar on it or something. Anyhoo, I attempted to flat back the sensing disc with some 1500 grit paper, re-installed it and attempted to start, and away she went. (with the solenoid valve disconnected) I then plugged the solenoid valve back in and within seconds the engine stalled! So, I'm wondering if I have some sort of earthing issue as well? Link to post Share on other sites
Smuggler 0 Posted August 4, 2008 Report Share Posted August 4, 2008 I wouldn't be inclined to believe that the charcoal solenoid is at fault just because it stalled after plugging it in, this could just be a the ecu adjusting because it's seen the valve connected and tried to change/adapt the fuelling, or the solenoid actuating and affecting the fuel.How about the starting issue, does it still not start? I had the exact same problem on my first VR6, sometimes wouldn't start when warm or would take 5 - 10 secs cranking over before starting. Turned out to be a crank sensor, also you can't often rely on whether the sensor looks ok or not, could still be knackered. Link to post Share on other sites
mrbeige 0 Posted August 5, 2008 Author Report Share Posted August 5, 2008 Indeed. I bought a new crank sensor yesterday (managed to wangle some discount and got it for £55 + VAT ) and fitted it. Took it for a run and seems ok, in fact it felt a little smoother, but I guess time will tell. Mrs B has the car today, so should be a good test for it. Link to post Share on other sites
thegoth 5 Posted August 5, 2008 Report Share Posted August 5, 2008 Indeed. I bought a new crank sensor yesterday (managed to wangle some discount and got it for £55 + VAT ) and fitted it. Took it for a run and seems ok' date=' in fact it felt a little smoother, but I guess time will tell. Mrs B has the car today, so should be a good test for it. [/quote']I hate those intermittent faults you are never sure you've fixed. Until it happens again and you know you haven't :@ Hope you have though Link to post Share on other sites
mrbeige 0 Posted August 5, 2008 Author Report Share Posted August 5, 2008 Indeed dude, indeed. I just hope it has fixed it. We have Mrs B's nieces down for the week and the last thing we want is the car to conk out on them in the middle of nowhere.Fingers crossed it sorted though :s Link to post Share on other sites
FishWick 21 Posted August 5, 2008 Report Share Posted August 5, 2008 VAG-com gave several errors' date=' including intermittent on crank sensor, fuel pump relay and all 6 injectors. I think that the injectors is a red herring though. [/quote']It's not a red herring though. I alread explained this to you, but for the benefit of others, with OBD2 the injector, MAF and fuel pump power supplies are all fed from pin Z1 on the relay board ONLY when a clean crank signal is receieved.VAG-COM was seeing a null voltage across the fuel rail, but isn't clever enough to realise it's because Z1 isn't powered up. Lose the crank signal, lose everything!You can tell when OBD2 is blocking Z1 because relay 167 will constantly click.Since the VR6's crank sensor is a magentic one (no power supply), it's voltage output will reduce with age. It's not unreasonable to expect them to die after 10 years.The ECU has a skipped signal threshold. It can only ignore a certain amount of signals and synch errors, then the engine will die. This random pattern of dying and non starting will only be cured by replacing the sensor. And I recommend the metal sensor from OBD1 Golfs / Corrados.The plastic sensors aren't as reliable. Link to post Share on other sites
mrbeige 0 Posted August 5, 2008 Author Report Share Posted August 5, 2008 Ah, Kev, when I said red herring, I meant as it being an actual fault as opposed to being caused by the lack of power on Z1, and thus caused by the dodgy engine speed sensor. Link to post Share on other sites
jws vr6 0 Posted August 5, 2008 Report Share Posted August 5, 2008 Ive put a crank sensor in mine yesterday of an old engine i have lying around and had it for a small run and seems ok so far, but the i thought the plug leads had fixed it till it died on me in the middle of town at lunch time! :$ So i'll give it a good run over the weekend and see hou it goes. Fingers crossed! Link to post Share on other sites
mrbeige 0 Posted August 5, 2008 Author Report Share Posted August 5, 2008 Cool, cool! Fingers crossed dude.Well, Mrs B has ben out and about today in her VR and its been behaving itself with the new sensor....so far. I'm not going to tempt fate though... Link to post Share on other sites
jws vr6 0 Posted August 16, 2008 Report Share Posted August 16, 2008 Seems to have sorted it! Link to post Share on other sites
mrbeige 0 Posted August 20, 2008 Author Report Share Posted August 20, 2008 Seems to have sorted it! Same here Link to post Share on other sites
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