CrazyDave 0 Posted August 25, 2007 Lots of people on hear complain of VR6 idling problems, cutting out etc etc. Now this is usual ISV, MAF etc but here's something I discovered today! I've had a fair bit of this on my own car just lately, and I always suspected it was the modifications I'd carried out. Well some of it is but I had a major breakthrough today that seems to have cured it! Motronic ECU's have a concept called 'calibrated air leaks' it has 4 separate MAPs to handle these situations. These are things that happen during certain conditions the engine encounters ie vapour recovery from the carbon cannister, the engine breather etc etc. Now when I fitted all my turbo stuff, I happily unpluged all these things thinking I wouldn't need them, plugged up the holes and blanked off the pipes etc. This is when my problems started. The ECU expects air to leak under certain conditions and if it doesn't it'll try to conpensate but not fast enough and by then the engine has stalled. Today I refitted my carbon canister and valve (with a slight mod to cope with having boost) and crank case breather pipe. It now idles perfect, doesn't stall when hot after driving hard etc. Great :) So if you are having problems with cutting out on a standard car. Have you removed the carbon canister? Removed the breather and dangled it down the back of the engine? These are all air leaks that the ECU expects to see, and will have a hard time adjusting if they've gone. Good eh! Quote Share this post Link to post Share on other sites
VR6 0 Posted August 25, 2007 Nice post Dave! Certainly something to try that's not going to cost you anything, which makes a change when it comes to these cars! My charged VR still seems to have the odd time when it decides that it will cut out, so I'll try hooking up the CC again. Quote Share this post Link to post Share on other sites
Toad 0 Posted August 25, 2007 Cool. Like that one Dave. Wonder how much carbon canisters are going to be worth in the future, now half the corrado owners have junked them? Quote Share this post Link to post Share on other sites
ZippyVR6 0 Posted August 25, 2007 Must be the weekend for breakthroughs with Idling problems. mine has been erratic for a while, Ive cleaned the maf and isv, but still wobbly revs at idle. I cleaned the k&n filter and re oiled it when it was dried out fitted it back on, All is fixed and she runs smooth again. Quote Share this post Link to post Share on other sites
CrazyDave 0 Posted August 25, 2007 Cool. Like that one Dave. Wonder how much carbon canisters are going to be worth in the future, now half the corrado owners have junked them? Probably don't need the canister as it's just the extra air thats needed, but I guess a percentage of the air has fuel vapour in it so might not be quite right without. I can see ££ signs in your eyes though! Nice post Dave! Certainly something to try that's not going to cost you anything, which makes a change when it comes to these cars! My charged VR still seems to have the odd time when it decides that it will cut out, so I'll try hooking up the CC again. Watch out if it's been mapped.Vince levels the maps so it might not have any effect. It's amazing how much Motronic has to cope with and it does a fair job most of the time. Usually takes a few changes before anything starts acting up. Quote Share this post Link to post Share on other sites
