tonytiger 0 Posted March 26, 2013 The lack of a lambda sensor shouldn't stop it running/revving - assuming the wires aren't shorted together. The ECU should detect the lack of signal and run a default fueling mode (rich). Also, for the first few minutes (2 mins I think) after starting the car, the signal is ignored anyway while the lambda sensor heats up. Have you had it on diagnostics as soon as you've got it started? Apart from checking for faults, in vagcom you can look at the 'measuring blocks' and see if the values look sensible. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted March 26, 2013 Also, for the first few minutes (2 mins I think) after starting the car, the signal is ignored anyway while the lambda sensor heats up. Correct! These are the conditions where the lambda is ignored:- During cranking / Startup (hot and cold) During warmup (to 70 deg C water temp) 3/4 throttle and above 4000rpm. Quote Share this post Link to post Share on other sites
timthetinyhorse 0 Posted March 26, 2013 Ok guys that's for the info, Another little update. I fitted the new lambda today and fired the car up, it started up straight away and sat at an idle of 1000rpm, I allowed the car to get warm (Until the fan pulled in) by which time the idol was sat at about 900rpm and still steady, I slowly brought the revs up to around 3000rpm and let them drop slowly using the throttle and they settle again at around 900rpm, I then did the same but let the revs drop off quickly by lifting straight off the throttle, they drop as expected but then the car struggles to hold idol and is lumpy for about 10-20 sec before it settles again. I didn't little experiment with the ISV by trying this with it plugged in and with it unplugged, on both occasions the car behaved in exactly the same way so I'm wondering if this could be my issue? I removed it and cleaned it out, a had a fair bit of dirt come out of it, it was the refitted and tried again and there was no change however the pipe clamps were damaged some could have a vac leek also now. The other thing I noticed was that when I removed the ISV it was about 1/4 open, is this the normal position for the valve or should it be shut? I have put a couple of before and after pics of t he valve from cleaning below this post so you might be able to see what I mean. The other think I noticed was a loud ticking noise when it was cold, this faded as the engine got hot so I'm wondering if I could have a sticky lifter? I'm going to check my oil levels tomorrow once the car has been sat so the oil settles as its possible I presume that if it is low on oil and the oil is cold the lifter may not be getting enough? Thanks for all the help so fat, I feel like I'm getting somewhere now :-) Quote Share this post Link to post Share on other sites
lewvw 10 Posted March 26, 2013 Yeah it's supposed to be slightly open. Careful though because it doesn't open that way it goes the other way. Quote Share this post Link to post Share on other sites
tonytiger 0 Posted March 26, 2013 Is the throttle damper working? When you let off the throttle suddenly, do the revs drop straight down to idle, or do they drop to a higher value first (maybe 1500-ish - can't quite remember) and then more slowly drop to idle? Quote Share this post Link to post Share on other sites
timthetinyhorse 0 Posted March 26, 2013 Leww how do you mean? Tony it drops a bit like you describe, might catch some revs then drops, what does the throttle do? Where is it? Cheers ---------- Post added at 10:39 PM ---------- Previous post was at 10:22 PM ---------- Infact the more I think about it no it dosnt, the revs just straight drop...... Quote Share this post Link to post Share on other sites
lewvw 10 Posted March 26, 2013 I mean if you open the isv to clean it, don't lever the gap, it rotates towards the gap. Quote Share this post Link to post Share on other sites
timthetinyhorse 0 Posted March 26, 2013 An ok I follow you mate, glad I didnt as I thought about it! Quote Share this post Link to post Share on other sites
timthetinyhorse 0 Posted March 27, 2013 Just had a look at the throttle damper and as far as I can tell its doing very little, if I open the throttle and release it the damper just compresses and does not slow down the lever with the wheel on, I have proved this by looking into the throttle and opening and releasing it, the throttle snaps straight shut, so from this (if I understand correctly) my throttle is snapping straight shut and not allowing the ISV to cycle and this the car is stalling or the revs drop dramatically below the idol point and take a while to settle. Hope I'm loooong at this the right way. The damper feels fairly good, when fully compressed it rises slowly, the only thing I can see is that the damper is compressed very little before it hits the throttle stop, am I correct in thinking if I lift the doer up a little it may function better? I'm sure everyone is sick of this thread but I need to sort this issue out ASAP. One last thing I did find is that I have a clamp missing off my exhaust at the rear before it goes over the rear beam and its blowing a fair bit, could this effect how the car runs?? I'm hunting for vac leeks also as the pipe work clips for my ISV are not good so don't go fully tight nor does the brake servo vac line above the fuel pressure regulator, I presume any one if these even having a slight leek could cause an issue? I will be getting some new clamps to fit Saturday I have tried to prove the maf by unplugging with the car running and when unplugged the car dies so I'm presuming the maf is ok by this? The crank breather line looks to be ok so I'm ruling that out (I had read in a few places this can cause an issue) Is there a simple way to locate a vac leek using some sort of smoke or similar or will this not work? Thanks in advance. Rob. Quote Share this post Link to post Share on other sites
tonytiger 0 Posted March 27, 2013 (edited) Exhaust blowing shouldn't affect the way the car runs. The throttle damper may be causing the stalling but it's not certain. If it's not operating correctly it won't help. As you say, you may be able to adjust it to improve the situation. However, I think lots of people have trouble with vr's stalling/cutting out with no guaranteed cure. The throttle position sensor could also impact it, if it's not correctly calibrated or not detecting when the throttle has closed (which you can check in vagcom). It sounds like the maf is working okay if the car dies with it unplugged - though I think the only way to be sure if a maf is working is to have it connected to an oscilloscope. A smoke test is a good way to find a vac leak, but I don't think they're simple or cheap to get done - or at least weren't when I looked at this a few years ago. You may find that no matter what you test and replace, you can't cure the problem. So the simplest thing to stop yourself going mad is probably to learn 'heel and toe'. Or at least do that for a while, then come back to tackle the problem later on. And in case you're wondering, I've been through all this myself - and I understand it's really, really irritating. I did find mine was much better for a good while after having some work done - I had the engine replaced!!! Edited March 27, 2013 by tonytiger Quote Share this post Link to post Share on other sites
timthetinyhorse 0 Posted March 27, 2013 How is the position sensor calibrated? I might just have to tax the car and take it for a drive and see what happens I suppose.......might open up more specific symptoms.....just hope I don't get stuck anywhere lol I have ordered some new clamps in case I have a bad joint somewhere as a few are poor and i might try to move the damper up a few mm just to try it. Cheers Quote Share this post Link to post Share on other sites
tonytiger 0 Posted March 27, 2013 It's been a while since I looked at this in detail - but you *might* be able to recalibrate the tps using vagcom, basic settings mode, but I can't remember. If you search the forum you may find some posts on it. The simplest way to tackle this, is to replace every sensor but that was too expensive for me at the time (and I wouldn't be too keen on doing it now). Hence reverting to heel and toe, which I learnt on my scirocco that had a pierburg carb where the auto choke didn't work. :lol: Quote Share this post Link to post Share on other sites
timthetinyhorse 0 Posted March 27, 2013 Looks like this may be what I have to do! I'm thinking it might be worth sorting the blow on my exhaust, taxing the car and taking it out for a drive to see if it's an issue that's occurred due to the car being sat for too long........ My car is a pure dry weather weekend car so it may just need a big run after being sat for the best part of 4 months? My wife informs me it's been off the road for more like 6 momth, I'm thinking it needs a run out Quote Share this post Link to post Share on other sites
