Solitaire 0 Posted March 7, 2006 Now i have the car running again, i need to sort the thing that caused the problem in the first place! have just had to fit a new ISV Damper, looking through the receipts, the car had one of these at 77K, just before i bought it, so this problem may have been happening for a while, anyway, the problem is, on start up, at first turn of the key, i sometimes hear a loud bang, which i believe is fuel exploding in the cylinder, as the car is overfuelling, MPG isnt that good, tho it varies on and off between 15MPG, up to 28MPG, and i am not that heavy footed! ...most of the time!!! anyway, looks like i may now have knackered the Cat, as since around september time, there has been a rattle under the car, getting progressively worse, Stealers thought the exhaust was knackered, so replaced with a Magnex, and noise is still there, apparently this also, can point to overfuelling, getting the Cat checked tomorrow, located a new one around the £100 mark, but have been told not to fit until the overfuelling prob sorted!! No fault codes pointing to overfuelling, Blue sensor, W025906041A was changed in july, new TPS in july, spark plugs (VW) done 11K, any help appreciated Cheers Guys, Caroline PS Car is 94 VR6 Auto, 86K Quote Share this post Link to post Share on other sites
Trig 0 Posted March 7, 2006 What is your O2 reading in VAG-COM? I have a similar thing ith mine but without the bang & it is caused by my ECU being broken... Quote Share this post Link to post Share on other sites
Solitaire 0 Posted March 7, 2006 Not sure, its going back to the garage on Thurs morn to be re 'vag-com'd, fault codes were cleared last week, and i was told to drive for a week and bring back, so took it to ultimate dubs sunday, for a bit of a run out, did ok, one of the guys at work did mention the ECU, (i work in the motor trade) but im hoping its not that, as i have already changed the Auto ECU, which took ages to get second hand, and i aint buying a new one!!! Quote Share this post Link to post Share on other sites
dr_mat 0 Posted March 8, 2006 If you have any fuelling problems, surely the lambda has to be the first potential culprit?? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted March 8, 2006 A bang on startup indicates a misfire through the intake, which explodes the ISV damper. Slack chains can cause that, although at 77K, they shouldn't be an issue. How are your plugs, leads, coilpack etc? Same old, same old I know, but they are critical on the VR. A defective lambda wouldn't cause a misfire through the intake, at worst a dudd lambda just gives you poor economy below 4000rpm. If you need a CAT, I have a perfect one which you can have for postage, it's just sitting in the shed getting in my way! Quote Share this post Link to post Share on other sites
Solitaire 0 Posted March 8, 2006 Cheers for the offer but the cats ok, had it tested today, the noise its been making is due to a cracked spot weld on the heat shield, which is rattling once the car heats up, not disintegrating insides as i thought! Plugs were changed at 76K, ive bought new leads today, so will ask the garage to fit tomorrow, KevHaywire, Cars done 86K, should i worry about the chain, as thought these never needed changing? VW history dictates the mileage to be genuine, Garage says if no fault codes are shown tomorrow, he is going to start with the injectors, as it must be something mechanical, the bang only ever happens on startup, and the car every other time has driven perfectly afterwards, except Wednesday when it blew the Damper, i am determined to get this car right, but have spent serious loads of money already, and the only modification so far is the exhaust, need a new set of wheels before the MOT in june, cause the tyres will need changing, seems the ideal time! Wondering if i should try and locate an ECU just incase? the cars obviously had the problem for a while, tho it is intermittent, if its had an ISV damper in the past? Quote Share this post Link to post Share on other sites
Solitaire 0 Posted March 9, 2006 ok, had the car in today to be re scanned, 1 fault code present, 00513, engine speed sensor - no signal, weird one this as a) it had one of these on 17/12 (Crank sensor at about £130) b) doesnt seem indictive of overfuelling problem? may explain why the gearbox still aint as smooth as i think it should be so guys, any ideas on the above 00513, if its had one anyway, or if this could be anything to do with the overfuelling? Quote Share this post Link to post Share on other sites
bcstudent 0 Posted March 9, 2006 Doesn't that just mean it was tested without the engine running? I don't think the car will run with a knackered engine speed sensor. Quote Share this post Link to post Share on other sites
Supercharged 2 Posted March 9, 2006 Hi Caroline, Yeah 00513 is G28 - the crank sensor so that must have come up with the engine off?? - If it was dead the engine wouldn't run at all... Maybe the auto's give slightly different fault codes to manuals - maybe worth checking the wiring anyway... Quote Share this post Link to post Share on other sites
Supercharged 2 Posted March 9, 2006 Oh and here is the link... http://www.ross-tech.com/vag-com/faq_1.html Quote Share this post Link to post Share on other sites
Solitaire 0 Posted May 31, 2006 Hi Guys, Car overfuelled again last week, ran rough for the first 10 minutes, then managed to drive to work, so didnt shatter the ISV damper again, tho this morning things got a little worse, car overfuelled again, and is now struggling to idle, seems to be trying to idle between 500 and 700 revs and keeps cutting out, once warmed up seems to stay running long enough to put into drive and set off, but i dont really want to chance it so swapped over to my escort van today, dont want to be driving it too long tho! so any help appreciated, opened the bonnet to check the ISV damper and it seems in one piece, could do with a list of problems which may cause overfuelling, without fault codes, and what could then cause the rough idle? Garage keeps suggesting injectors, and told me it probably wouldnt overfuel in the warmer weather! have just fuelled up and put in some injector cleaner, but only done about 50 miles, does seem quite a strong fuel smell whilst the rough idle is happening. Everyone wants me to sell this car but i have to keep trying, know you will all understand..... Quote Share this post Link to post Share on other sites
steveoxford 0 Posted May 31, 2006 I've had the exploding ISV damper problem a few times. Very unpredictable. My understanding as to the cause is induction explsion due to fuel leaking in to a cylinder past an injector. As the VR6 uses wasted spark ignition system, you will get a spark with an inlet valve open causing the explosion. It only happened a few times, but i did get through a few dampers. I fitted a Schrick so no damper anymore but i do get the bang sometimes. Mine only started doing it originally after i had my injectors serviced!!!!!!! To cure a misfire which ended up being the coil. Quote Share this post Link to post Share on other sites
Solitaire 0 Posted June 16, 2006 Guys, The cutting out is still happening since the overfuelling over a week ago, was at the garage Thursday, and they have disconnected the electical plug from the ISV, as cleaning the ISV had no effect, car does run a little better (smoother on idle) with the ISV unplugged, but is still cutting out, so does this point to a faulty ISV?, tried to find the Blue Temp sender today as that has been mentioned as a probable fault, but it didnt seem to be in the same place as on the car i looked at at the show in Shrewsbury, my car is an auto, would that make a difference, or am i just not looking hard enough? Also, just for the record, indicators decided to stop working this morning, went to check the fuses, and relay 21 fell to the floor with the prongs a bit bent, straightened out, refitted and indicators work perfectly, not been near the fuseboard! so cant quite work out how it ended up in that state, but there you go, thats corrados for you...... Quote Share this post Link to post Share on other sites
VRTrickster 0 Posted July 16, 2006 Solitaire, Have you sorted your problems out yet mate? Quote Share this post Link to post Share on other sites
Solitaire 0 Posted August 7, 2006 VRTrickster no probs not sorted yet! Fitted the coolant temperature sensor (blue) four weeks ago, no difference, then had a replacement ISV fitted 3 weeks ago, which meant the car started and ran perfectly again, thought my problems were sorted, and i was enjoying the VR6 on the way to work again, until thursday, car overfuelled on startup, one ISV wrecked again, garage tryed cleaning it with brake cleaner, no better, so im after another ISV and to prevent further expense, would love to get to the bottom of the overfuelling problem once and for all, if you have any ideas it would be very much appreciated! Am thinking maybe injectors or lamda probe, or worse... ecu? Im now corrado less for the next week or so as the auto gearbox i had fitted in October is playing up a little and getting repaired under the warranty, car runs slightly lumpy when warmed up, but wont stall. Ive had a year of problems with this car, and a civic type R is looking increasingly tempting, please restore my faith in VW...... Quote Share this post Link to post Share on other sites
