eugopnosaj 0 Posted November 22, 2011 OK guys, went to start the VR and as i turned the key i heard a pop, it was kind of mid-high pitched and ever since the car won't start on its own, it sounded like a hose coming off or something under pressure but the engine was cold, its not cold enough for the water to freeze and there aren't any leaks visible. It will start with throttle but wont idle and it then dies. There is a strong smell of fuel afterwards. I have checked the fuses and they all look fine so the pop wasn't one of those, plus the sound came from the engine bay. I've had the bonnet up and had a quick inspection with a torch and cannot see anything amiss. I put her on VAG-COM and it flagged up:- 533 - Idle Speed Regulation and another one starting in 5xx but i can't remember which one it was and in my hurry i didnt save the codes. W towed the car to my dads so i cannot check VAG-COM again till tomorrow. Any ideas what it could be causing it not to start and also what might have gone bang! Quote Share this post Link to post Share on other sites
floppyman 0 Posted November 23, 2011 It sounds your isv has gone. The popping sound was probably a back fire. When you plug vcds in go into engine and then output test. Press next till you get the iddle stabilization valve and the check it to see if its clicking. Quote Share this post Link to post Share on other sites
Supercharged 2 Posted November 23, 2011 Sounds like the ISV damper pots exploded... http://the-corrado.net/.archive/forum/viewtopic.php?f=1&t=54565&hilit=isv+damper+pic Quote Share this post Link to post Share on other sites
VR6 0 Posted November 23, 2011 ^^ Second picture down Quote Share this post Link to post Share on other sites
eugopnosaj 0 Posted November 23, 2011 Sounds like the ISV damper pots exploded... http://the-corrado.net/.archive/forum/viewtopic.php?f=1&t=54565&hilit=isv+damper+pic Ugh, I hope the damper didn't explode as I've only just replaced it as the one that came with the car was all cracked :(. I've got a spare isv so can test that but why would it have popped? Quote Share this post Link to post Share on other sites
eugopnosaj 0 Posted November 23, 2011 Took the ISV and the damper box off, the foam from inside the box had been pushed out into one of the pipes blocking it. We removed the foam and gave it a clean, man was it dirty! Anyway cleaned it up and reattached it with the original ISV. It started with a bit of throttle so i turned her off and started it up without throttle. Again she started and after watching the revs fluctuate slightly she stalled. Started it again and it was better but i wasn't convinced as the revs still seemed high. So we tried the spare ISV in the garage but that turned out to be knackered so binned that. Tried the original ISV with a 12v battery in the garage and although it opened, it didn't open fully, there was still about 1mm left before it was fully open. So I took the ISV off of my 16v (same part numbers) and did the same test, it opened fully so I fitted that one instead. Started the VR and she started fine, revs were good, took it for a drive and she responded well. Connected VAG-COM and checked all the readings and they were pretty good. I think perhaps the ISV needs another clean, i had removed it before and gave it a bit of a clean when I replaced the damper box but maybe it needs something a bit more thorough...At least she starts again and i can come along to the RR day! :) Quote Share this post Link to post Share on other sites
Supercharged 2 Posted November 23, 2011 Good bit of troubleshooting there! I think ISV's wear out after a while, especially if the car has had a K&N filter or similar. Quote Share this post Link to post Share on other sites
eugopnosaj 0 Posted November 23, 2011 Well, strangely the VR has only done 142k and has a standard airbox (well it has had the carbon canister deleted and a cold air feed added instead) , whereas my 16v has done 174k, again with a standard airbox, neither looked to have had a new ISV as both looked worn. Now I've got a bit of research to do about ISV part numbers.... Quote Share this post Link to post Share on other sites
robrado974 1 Posted November 23, 2011 Thinking of replacing mine as well , the revs can be a bit sketchy at times Quote Share this post Link to post Share on other sites
Wendy 0 Posted November 24, 2011 See I said you had plenty of time to fix it !!!! See you on Sunday Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted November 24, 2011 Is there any foam stuck in the ISV?. I've had a couple off ebay with foam chunks stuck in them, which stops the valve opening and closing properly. Get a bright light in there whilst moving the valve manually and see if you can see anything in there. The 16V ISV might work in the short term but some ISVs require a flyback diode and it also might not have the same range of movement and flow to cover all the scenarios mapped into the VR6 ECU. I wouldn't stick to the VR6 valve if possible. If it's exactly the same valve (Bosch number more important than VW one) then it should be fine. I would remove the ISV damper pot personally as it's more of a hinderance than a help. Quote Share this post Link to post Share on other sites
eugopnosaj 0 Posted November 24, 2011 The part numbers on the ISV i took from the valver are identical to the ones on the VR ISV, not sure why that is the case but worked well for this scenario. I will give the one from the VR a really good clean. What makes the damper box such a hindrance? Quote Share this post Link to post Share on other sites
