VR6Bella 0 Posted October 11, 2006 Early VR6 is hunting while cold (with threat of cutting) and cutting out when hot, also having issues starting (delay on start and then hunts for a count of 10) and worse when wet. I have changed all I can think of over the last 6 - 9 months and the ECU is now not giving any more clues as to what might make it a happier car. List of changes so far are as follows: Changed fuel pump and associated parts Knock sensors changed Throttle Potentiometer changed HT leads changed Tried Platinum plugs / tri spark plugs and normal to no effect Changed Distributor cap and arm Throttle valve cleaned (think there is a better name for this but cannot think what it is!) Tried every fuel under the sun and it doesnt really effect l/t Tried taking for long runs / short runs Changed Module / amplifier for coil Tried running on Red ex and other injector cleaners again to no real effect Could it be ECU / Temp related? Any other ideas as am now coming into winter and its not getting any drier / better and I've tried all suggested by previous topics on forum! :( Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted October 11, 2006 How does that rule go? "Once the something something is outruled, the simplest explanantion must be the right one" or something like that..... Alan's Rule or something? Anyway, as you've outruled everything, what's left that you haven't? MAF Quote Share this post Link to post Share on other sites
2corrados 0 Posted October 11, 2006 HI sounds like the liturgy of problems I was having with mine, but I had the addition of smoking like a piggggggg.............bores gone. I was diagnoised with temp sensor problem originally, so changed that, but to ne effect cos the idiot at the garage put the wrong one in. Use gen VW if you do. Try a compression test, just to see whats going on, should be around 125 plus on each cylinder, but this depends on wear etc. Takes about 30 mins to do, and a tester is about £18. saves spending any more until you know. Mine is being rebuilt at the mo, at vast expense.........but i know she is worth it. Good luck Dic Quote Share this post Link to post Share on other sites
VR6Bella 0 Posted October 12, 2006 2Corrados - which temp sensor was put in / was needed to be put in? Mine do look corroded but finance getting tight and am reluctant to change all three sensors if not needed! No smoke (yet!) and when its running fine it is purring - but when bad it is very, very bad! (10 mile run cut out dead 4 times this morning!) Quote Share this post Link to post Share on other sites
Taggart 0 Posted October 12, 2006 Just one quick free thing to check - The ISV damper has a bit of foam in, check it hasn't come loose and blocked to pipe going to the ISV. This was the cause of mine idling poorly and cuttng out. Quote Share this post Link to post Share on other sites
vr6storm 0 Posted October 12, 2006 just noticed yer sig has it has a 91 VR6...............is it a conversion???..........the reason I ask is.......if its not a conversion then you should be able to get it scanned on VAG-COM to find out if it is a temp sensor thats gone......it does sound like its the ECU temp sensor to me....around £30-ish for one and 30mins tops to fit Quote Share this post Link to post Share on other sites
2corrados 0 Posted October 12, 2006 temp sensor on the left as you look at them from the front, in the thermostat housing. 4 pin connector. remember to replace coolant with correct type ie G11, now upgraded to G12 I believe. easy job, but do it when cold, and maybe save having to replace all coolant, but make sure you get new rubber o ring for sensor. Dic Quote Share this post Link to post Share on other sites
vr6storm 0 Posted October 12, 2006 make sure its G12+ you use not G12................. Quote Share this post Link to post Share on other sites
2corrados 0 Posted October 12, 2006 sorry forgot to type the +, nearly catastrophic ehh ? I promise not to do it again................slap my own wrist Quote Share this post Link to post Share on other sites
VR6Bella 0 Posted October 13, 2006 VR6Storm - No not a conversion - the ECU wasn't reading any more codes (2 weeks ago) - but will get it read again this weekend and see if any more have appeared am assuming that won't be as this issue has been going on for soo long! xbones - am borrowing another ISV at the weekend to try so will check foam status. Quote Share this post Link to post Share on other sites
vr6storm 0 Posted October 13, 2006 VR6Storm - No not a conversion - the ECU wasn't reading any more codes (2 weeks ago) - but will get it read again this weekend and see if any more have appeared am assuming that won't be as this issue has been going on for soo long! . strange.........I'm assuming its a Corrado VR6 here..........the only 91 CVR6's will be LHD/german market ones........the CVR6 wasn't launched in the UK til late summer 1992 Quote Share this post Link to post Share on other sites
VR6Bella 0 Posted October 13, 2006 Yep VR6 but 1001 car on a 1992 plate - however does have full ECU with distributor. Have been told by a couple of people who seen it that it is a strange mix and must have been right on clusp! What does the C in CVR6 stand for? Quote Share this post Link to post Share on other sites
VR6Bella 0 Posted October 13, 2006 Ah - ok suffering from Friday feeling - sorry stupidity setting in! Quote Share this post Link to post Share on other sites
VR6Bella 0 Posted November 16, 2006 Ok have now changed ISV and temp sensor with VW ones and still no difference! Any other ideas? Compression test kit on order! Would it have a lander sensor? Would this have an effect? Quote Share this post Link to post Share on other sites
Supercharged 2 Posted November 16, 2006 Have you changed the MAF? Quote Share this post Link to post Share on other sites
2corrados 0 Posted November 16, 2006 yes should have a lambda sensor, bit of a git to get at, but a good replacement is about £55. Yes could have an effext, but i believe sensor only comes into ecu computations when engine is hot, so not gonna make a difference at cold. Did you check pipes and "muffler" between air intake and isv. Make sure its clean and not blocked. Leak down compression test is better but takes longer and invloves more, but a compression test to start is good. Good luck Dic Quote Share this post Link to post Share on other sites
VR6Bella 0 Posted November 17, 2006 I have changed the MAF and ducting to it. Had a big hole in the ducting next to it so that did make a differnce! Have also checked other areas on the air intake as much as has been possible and nothing seems blocked. Is VW the best place to get replacment sensor? Now that made all changes it is definatley happening more when hot than cold - so this could be the final change! Any clues on how to go about it? It has had exhast and cat changed to a miltech stainless set recentley so am hoping all would not be too clogged up! Quote Share this post Link to post Share on other sites
2corrados 0 Posted November 18, 2006 i got my lambda sensor form a local car parts supplier. It was NGK i believe. Access is awkward unless you have a pit, or ramp, but electrical connectors are simple. Give it a go, and see what happens Dic Quote Share this post Link to post Share on other sites
VR6Bella 0 Posted November 20, 2006 Are there any pointers as to locating the sensor? Quote Share this post Link to post Share on other sites
vr6storm 0 Posted November 20, 2006 should be sticking out of the Catalytic converter Quote Share this post Link to post Share on other sites
2corrados 0 Posted November 20, 2006 on the top side towards the front................owww, theres another knuckle gone........ Quote Share this post Link to post Share on other sites
VR6Bella 0 Posted November 21, 2006 Knuckle / nail its all the same - would be a good sacrifice if the car runs straight! Quote Share this post Link to post Share on other sites
STORM 2 0 Posted December 27, 2006 How does that rule go? "Once the something something is outruled, the simplest explanantion must be the right one" or something like that..... Alan's Rule or something? Anyway, as you've outruled everything, what's left that you haven't? MAF I think this is what youre looking for Kev Ock·ham's razor also Oc·cam's razor : A rule in science and philosophy stating that entities should not be multiplied needlessly. This rule is interpreted to mean that the simplest of two or more competing theories is preferable and that an explanation for unknown phenomena should first be attempted in terms of what is already known. Also called law of parsimony. [After William of OCKHAM.] Quote Share this post Link to post Share on other sites
VR6Bella 0 Posted February 28, 2007 Well not sure what has happened but to close the loop the car now runs straight! Waterpump bearing collapsed and after trying to drive with smoke from belt and screaming from pump made choice of asking a very nice AA man to get me to garage a very easy choice to take. Had water pump / belt changed (thanks to Mark Tempest Autocenter for not only doing a great job but doing it quickly too!) and it hasn't hunted since (although am touching wood while typing this)! :thumbleft: Thoughts have been - water pump now doing its job so temp sensors are reading right, or a dodgy wire was released / trapped when engine was lifted to change the pump and now wire sending correct readings? So still not sure which of the simplest explainations explained this one - just am glad that the car is straight (for now!)! Quote Share this post Link to post Share on other sites
