VRTrickster 0 Posted January 27, 2007 Right, I just forked out £325 for a custom re-map yesterday after extensive head work and cams etc. The car was make good power 215bhp before the map and then 230bhp 200 lb ft of torque after ! The thing that concerns me is that it was cutting out rather a lot before the map, nearly every junction! When I got it to Stealth, Vince was puzzled that he couldn't sort out the stalling problem as simply as other VRs with the same problem ! All sensors are fine and a lot have been replaced due to the cutting out including fuel pump and reg. Vince was able to make changes to the map to help the problem, and it did reduce the stalling somewhat when hot but the problem still persists when cold! After I received the head back and built the car back up and ran it for a few miles I gave it a compression test to find that the pressures were good, the front three pistons were equal to each other as were the rear set but there is a bar difference between the front and back set. I was wondering if this has anything to do with the rough idle and it cutting out!? Could this imbalance be due to the flow work carried out on the head ? I will contact the man who carried out the work on the head for advice. This is obviously a great annoyance as I have spent a great deal of time and money on it and am having to take it apart again. Any advice on this matter would be much appreciated. Quote Share this post Link to post Share on other sites
VRTrickster 0 Posted February 4, 2007 Well it looks like it was the MAF causing the cutting out after all Kev ! It doesn't cut out at all now which is great, and it f-ing flys which is even better ! I'm not too worried about the comp test as I might not of opened up the throttle whilst carrying it out or something ? The question is now could this be why my torque was just above average after the map ? Would the dodgy MAF of caused the dip in torque between 5 and 6k ? Could the fault of affected the power also? I'm so happy this has been resolved, I can now start enjoying the drive ! Thanks to everyone who helped with advice ! Quote Share this post Link to post Share on other sites
antera309 0 Posted February 4, 2007 The thing that concerns me is that it was cutting out rather a lot before the map, nearly every junction! When I got it to Stealth, Vince was puzzled that he couldn't sort out the stalling problem as simply as other VRs with the same problem ! He asn't able to sort the stalling on mine (280BHP Stg2 OBD1 2.8), which is really bad, hot or cold. Did he manage to sort the problem out on your engine? What did he do? Do you think a brand new MAF might make a difference? Quote Share this post Link to post Share on other sites
Taggart 0 Posted February 4, 2007 From all I've seen, I've never trusted the dyno at Stealth. I'd trust them to do work on my car, just their machine seems to throw up odd results. Quote Share this post Link to post Share on other sites
CorradoVR6-Turbo 0 Posted February 4, 2007 Ive got no Maf or idle valve and mine has Never Stalled .. Quote Share this post Link to post Share on other sites
antera309 0 Posted February 5, 2007 Ive got no Maf or idle valve and mine has Never Stalled .. My MAF is still connected and the ECU map requires it to be that way. Do you think losing the idle valve might help? Do you have your throttle bypass hoses blocked off completely? From all I've seen, I've never trusted the dyno at Stealth. I'd trust them to do work on my car, just their machine seems to throw up odd results. Who do you take your car to for remapping work, xbones? I would definitely like to seek a second opinion on the ECU side of things. Quote Share this post Link to post Share on other sites
VRTrickster 0 Posted February 5, 2007 The thing that concerns me is that it was cutting out rather a lot before the map, nearly every junction! When I got it to Stealth, Vince was puzzled that he couldn't sort out the stalling problem as simply as other VRs with the same problem ! He asn't able to sort the stalling on mine (280BHP Stg2 OBD1 2.8), which is really bad, hot or cold. Did he manage to sort the problem out on your engine? What did he do? Do you think a brand new MAF might make a difference? As I said above, it was the MAF causing my problem. I think its hard to diagnose unless it packs up all together ! Its definitely worth thinking about ! Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted February 5, 2007 If the MAF is connected but operating out of range, it can cause problems, particularly at low rpms and idle, where the injector duty and air flow are very low. If the MAF has been mapped out of the equation, the TPS and lambda take over, but the engine can't detect load. Glad yours is sorted now Trickster mate! I shouldn't worry about your torque, it looked good to me. Torque is actually what is measured on the dyno, everything else are meaningless numbers. Dynos should be seen as a tuning tool, rather than a true measure of engine output. The way your head now flows and also the free breathing cams can affect your torque output. You've kind of created yourself a VTEC motor, lots of revving at the slight expense of torque. In normally aspirated engines, slowing down gas flow by derestricting the intake can reduce torque in many instances. You've got a great engine there mate, nothing to worry about. From all I've seen, I've never trusted the dyno at Stealth. Why? The results always seem consistent to me, in the context of the cars run on it. I'd trust them to do work on my car, just their machine seems to throw up odd results. So many things affect readings. Stealths Sun Rollers are among the most accurate in the business. If anything is odd, it will be the car, not his rollers. Having dyno'd my car myself on those rollers, it's not as easy as it looks and user error can influence the figures as much as anything else. Quote Share this post Link to post Share on other sites
VRTrickster 0 Posted February 5, 2007 Glad yours is sorted now Trickster mate! Cheers mate Im pleased as well! :) Just one thing though, it cut out for the first time today and the idle is still a bit lumpy. I actually just stuck back on the original MAF the car had when I brought it, and I was wondering if buying a new one would improve things more so ? Quote Share this post Link to post Share on other sites
VRTrickster 0 Posted March 8, 2007 Right it seems that my running problems just don't want to be cured! I have replaced many parts, sensors etc and still I have cutting out and lumpy idle! Here's a list of what has been done or replaced recently : NEW ITEMS IGNITION LEADS VW ISV VW PLUGS NGK CAM PS AND PICK UP VW LAMBDA GSF FUEL PUMP RELAY ECU RELAY COIL PACK TPS TRIED NEW ING SWITCH FPR VW FUEL PUMP FUEL FILTER BLUE TEMP SWITCH SECOND HAND ITEMS MAF X2 ECU COIL PACK INJECTORS WORK CARRIED OUT FULL HEAD REBUILD CHECKED OR VAC LEAKS ETC REMAPED BY VINCE STEALTH It seems to start up quite roughly and recently started hunting for idle revving up and down between 650-1000. It doesn't seem sluggish and runs fine on the motorway etc. When slowing down coming up to a junction or lights, it just dies, the revs drop fast and the red lights come on! When coasting just drop the clutch and it cuts out. It starts up straight away but I still feel as though it turns over quite a lot before sparking, which I'm not sure if that's the norm for VRs, but it can take 2-3 secs ? It has on maybe two to three occasions cut out and then refused to spark! But after a couple of attempts starts again This made me start thinking that it could be the crank sensor playing up ? I must say that I don't think that the second hand MAFs have been any good either so that could still be the problem. I don't suppose anyone on here, that doesn't live that far from Brighton, has got a good MAF I could try, as I cant really afford a new one if it isn't the cause of this year long annoyance !! Ill be fitting a new crank sensor on Saturday so that will add another thing to the list. I really don't think there's much left to try ? Any advice is greatly welcome ! Quote Share this post Link to post Share on other sites
