pbradley98 0 Posted January 29, 2013 (edited) Hi, Wondering if anyone else has experienced this... Had an issue with stalling when de-clutching in that sometimes the revs dropped just too low when declutching, resulting in a stall. Fitted a new damper between the ISV and the air inlet which made a big difference, but still had the occasional stall so managed to get a brand new ISV on here (aftermarket rather than genuine vag, but is so similar wouldn't be surprised if it was the same manufacturer). Due to the Baltic weather, didn't fit it and during that time the stalling pretty much went away, which I'm guessing was the ecm learning and correcting itself. Finally got round to fitting the new one at the weekend and the stalling has come back! The only thing I can think of is that the old ISV had a higher amount of leakage when in the fully shut position, so the ecm learnt when to open the valve to prevent a stall based on there already being a small amount of air flow passing through even when in the fully closed position. Now the new ones fitted I'm guessing that there's less leakage, so the valve needs to be opened fractionally earlier? Can anyone advise if this is a possibility and should I stick with the new one to let the ecm learn and hopefully have no worries about it dying anytime in the near future or should I go back to the old ISV that's already covered 150k given it didn't stall?!! pretty sure it's not the maf as that was replaced about 18 months ago... Cheers Phil Edited January 30, 2013 by pbradley98 Quote Share this post Link to post Share on other sites
pbradley98 0 Posted February 19, 2013 Decided to leave the new ISV on and is now significantly better after a couple of weeks driving (hope they're not famous last words!) - whilst it still very occasionally dips, manges to keep the engine from stalling and pulls it back to around 600rpm where it then stays happily. Still interested if anyone can shed any light on my theory above? Cheers Phil Quote Share this post Link to post Share on other sites
nrc 0 Posted February 19, 2013 I'm not sure about the ISV control but do you possibly have any leaks in the air intake after the MAF, e.g. the breather hose? Any fault codes logged for mixture adaptation limits exceeded? Quote Share this post Link to post Share on other sites
Supercharged 2 Posted February 19, 2013 Have you been through the basic settings procedure? Quote Share this post Link to post Share on other sites
Jim 2 Posted February 19, 2013 Might be worth disconnecting the battery for an hour or so to reset the ECU. Then get it connected back up and take the car for a good drive and see how that works out. Quote Share this post Link to post Share on other sites
pbradley98 0 Posted February 20, 2013 Hi Guys, Thanks for the replies.... I'm not sure about the ISV control but do you possibly have any leaks in the air intake after the MAF, e.g. the breather hose? Any fault codes logged for mixture adaptation limits exceeded? Haven't got anything to check the fault codes with, but couldn't hear any leaks post MAF in the intake - originally took everything off between the MAF and the throttle to clean it all up and put it all back together (there was a slight oil leak from the breather onto the exhaust manifold heatshield which now looks to be resolved by the strip and clean), so don't think it's that but may try for a second opinion from someone with more experience than me! Have you been through the basic settings procedure? When it first started happening it was because the battery had died so went through the basic settings and it improved it, but the stalls still happened. Found that the ariflow damper post ISV was shot to pieces, so replaced that with a brand new one from the dealer which made a big difference (especially when first fitted, was idling at about 1200, rising to about 1400 before dropping and then doing it all again for about the first couple of minutes before presumably the ECM learnt and adapted the ISV position to suit). Did basic settings again then, but still had the occassional stall afterwards hence why I got the new ISV too - in hindsight should have done basic settings again once I fitted the new ISV but didn't think of that at the time! Might be worth disconnecting the battery for an hour or so to reset the ECU. Then get it connected back up and take the car for a good drive and see how that works out. Hasn't stalled since before the monthly meet, so think that the ECM has learnt enough through use so am going to leave it as is whilst it's behaving! If it starts playing up again will try the basic settings, but whilst it's behaving itself.....! Was more interested if anyone could shed any light on my theory why the new ISV was worse than the old one when first fitted! PS - Jim - following last week at the pub listened out for the spoiler at 56mph this morning (even turned the radio off!) but couldn't hear it at all! Quote Share this post Link to post Share on other sites
pbradley98 0 Posted July 30, 2013 Following stalling issues earlier this year and replacing ISV, ISV damper and done an ECU learn, all seemed good (additionally MAF replaced 2 years ago), I now think that the blue temp sender is on the way out, as stalling at idle has started again! This only happens when the engine is cold, so having read up various threads on here guessing this is either the MAF or the Blue Temp sender. Tried disconnecting each one at the weekend - without the MAF couldn't keep the engine running even when applying throttle, whilst without the temp sender the engine would run but the idle speed dropped to ~550rpm from it's usual 650rpm. So question is do the Blue temp senders get less accurate with age? And hence best bet is to try replacing this first, additionally this is a lot less than MAF replacement! Only other thing is have recently swapped to a Jetex panel filter (just before the problem started so slightly suspicious) and read somewhere that these have some oil on them, which could contaminate the MAF? I'm nervous about thrying to clean the MAF element, as I don't want to do more damage than good as after a couple of minutes of running, all is fine! Any advice appreciated... Cheers Phil Quote Share this post Link to post Share on other sites
seanl82 23 Posted July 31, 2013 The "wet" type longlife filters are reported quite alot to kill MAFs. Give the filter a clean, but don't re-oil it. You wont do damage by not oiling it, even though the oil is supposed to stop even more dirt particles passing as it clings to them. Take the MAF off and give it a spray over with electrical contact cleaner too. What is the ISV damper? (forgive my ignorance). Is it the TB damper what yor talking about? As that could cause revs to drop too low. A bit of careful tweeking as its adjustable may raise the revs by a couple of hundred and leave you without worry, or the damper itself may be shot and need replacing. Quote Share this post Link to post Share on other sites
pbradley98 0 Posted August 2, 2013 Hi, Thanks for the response. Will get some cleaner and give that a go. The Damper I've already replaced is between Isv and the inlet, not the throttle body damper... Cheers Phil Quote Share this post Link to post Share on other sites
pbradley98 0 Posted September 29, 2013 Just a quick update - touch wood the issue has now gone away, seemed to be getting better and also gave the MAF a clean as suggested (well, Vince did as the car had to go into Stealth for an emergency clutch repair so two birds...), which would give weight to the oil from the filter just reducing the accuracy of the MAF.... Cheers Phil Quote Share this post Link to post Share on other sites
