Jezz Posted October 2, 2006 Share Posted October 2, 2006 I'm getting a strange hesitation on half throttle between 3k-4k revs. Also sounds like a 'miss' until i accelerate a little harder. Car was running sweet up until last thursday when i put some Bp ultimate in. 10 miles later it started hesitating. Really noticable on the motorway and in 4th and 5th. Car is Bpu with blitz access ems. Any ideas? Quote Link to comment Share on other sites More sharing options...
squiffy Posted October 2, 2006 Share Posted October 2, 2006 my auto tt hesitiates now but only when flat out and it has just changed into 4th had been on bp ultimate and never done it, now on shell v-max?? Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted October 2, 2006 Share Posted October 2, 2006 Im the same, i reckon its to do with the changeover betweeen the 1st and 2nd turbo, maybe BPU makes it more apparent? Quote Link to comment Share on other sites More sharing options...
Kopite Posted October 2, 2006 Share Posted October 2, 2006 Something related to the fuel? I know my UK car hated BP Ultimate whereas the J-spec loves it. Could be due to ignition depending on your fuelling for BPU though. You got an AFR gauge? Quote Link to comment Share on other sites More sharing options...
Jezz Posted October 2, 2006 Author Share Posted October 2, 2006 No AFR gauge yet. Probably be my next purchase. Its just strange that it started after putting the Bp stuff in. Quote Link to comment Share on other sites More sharing options...
Class One Posted October 2, 2006 Share Posted October 2, 2006 No AFR gauge yet. Probably be my next purchase. Its just strange that it started after putting the Bp stuff in. That and the fact that you rag the fuck out of it! Quote Link to comment Share on other sites More sharing options...
Jezz Posted October 2, 2006 Author Share Posted October 2, 2006 That and the fact that you rag the fuck out of it! Only in a private car park officer. Quote Link to comment Share on other sites More sharing options...
Kranz Posted October 3, 2006 Share Posted October 3, 2006 Its been raining a lot lately. My bet is the underground tank in the petrol station has probably got water in it, so you've bought petrol & water mix. I once had this in a Mini. Pulled the choke out to richen the mixture and it went away. More fuel = problem solved. Probably doesn't do it at low throttle as the ECU is running off the lambda sensor so corrects the mixture to run richer and gets more fuel in to compensate for the water content. At full throttle you're probably way rich on the fuelling anyway, and the water content will supress any bad effect such as detonation due to going lean (if it does go anywhere near lean, full throttle is very rich on Supes). That leaves part throttle where the lambda sensor isn't being used to adjust the fuelling quantity, but the mixture is running mid way between stoich and full power rich. The water content is leaning out the mixture too much & quenching the flame (if it fires at all) causing misfire. Fill up with petrol from another station ASAP & use it up. If it doesn't do it after the next tankfull then it's probably this water problem If you're worried there may be engine damage take a sample of the fuel as it is now to prove your case against the garage that sold you the fuel. I can have it analysed. Quote Link to comment Share on other sites More sharing options...
Thorin Posted October 3, 2006 Share Posted October 3, 2006 Hesitation is almost always ignition based IMO. Check your plugs. Quote Link to comment Share on other sites More sharing options...
Jezz Posted October 3, 2006 Author Share Posted October 3, 2006 Its been raining a lot lately. My bet is the underground tank in the petrol station has probably got water in it, so you've bought petrol & water mix. I once had this in a Mini. Pulled the choke out to richen the mixture and it went away. More fuel = problem solved. Probably doesn't do it at low throttle as the ECU is running off the lambda sensor so corrects the mixture to run richer and gets more fuel in to compensate for the water content. At full throttle you're probably way rich on the fuelling anyway, and the water content will supress any bad effect such as detonation due to going lean (if it does go anywhere near lean, full throttle is very rich on Supes). That leaves part throttle where the lambda sensor isn't being used to adjust the fuelling quantity, but the mixture is running mid way between stoich and full power rich. The water content is leaning out the mixture too much & quenching the flame (if it fires at all) causing misfire. Fill up with petrol from another station ASAP & use it up. If it doesn't do it after the next tankfull then it's probably this water problem If you're worried there may be engine damage take a sample of the fuel as it is now to prove your case against the garage that sold you the fuel. I can have it analysed. Interesting. Gone through £60 of sainsburys finest and still no difference. Might try draining it all out first. Hesitation is almost always ignition based IMO. Check your plugs. Nice one. I'm on it now. Quote Link to comment Share on other sites More sharing options...
Jezz Posted October 3, 2006 Author Share Posted October 3, 2006 Plugs say its running sweet?? Quote Link to comment Share on other sites More sharing options...
keron Posted October 3, 2006 Share Posted October 3, 2006 i would say check the spark plug gapping...incorrect gapping will cause it not to run smooth... also i dont get on with bp ultimate fuel either as it makes the car run like shite! Try to use shell optimax... Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted October 3, 2006 Share Posted October 3, 2006 Try to use shell optimax... That is soooo last week V Powah is where its at Quote Link to comment Share on other sites More sharing options...
Jezz Posted October 3, 2006 Author Share Posted October 3, 2006 Plugs are brand new. Only fitted the other week. The slight hesitation has now turned into a full on missfire and loss of power under acceleration. I get the 'pops' when turbo 2 comes on boost all the way to the redline. Darn it! Really wanted a run on sunday too. Quote Link to comment Share on other sites More sharing options...
Rich Posted October 3, 2006 Share Posted October 3, 2006 Plugs are brand new. Only fitted the other week. The slight hesitation has now turned into a full on missfire and loss of power under acceleration. I get the 'pops' when turbo 2 comes on boost all the way to the redline. Darn it! Really wanted a run on sunday too. coil pack issue,or connectors? Quote Link to comment Share on other sites More sharing options...
keron Posted October 3, 2006 Share Posted October 3, 2006 sounds like the same problem as mine.....although the plugs a new you should always check the gapping on them before you put them in as they may not be correct.... mine were brand new (hks) and 2 of them had different gapping to the rest...sorted the gapping out and it sorted my problem out.... Quote Link to comment Share on other sites More sharing options...
Jezz Posted October 3, 2006 Author Share Posted October 3, 2006 coil pack issue,or connectors? Bingo! Just checked all my coil packs, one plug is completely disintergrated and another wasnt far off being screwed. Got rid of all the crap plastic, slid the pins onto the connectors and filled the plug with silicone. Now running beautifully again. Cheers guys. Are coil pack connectors a common issue? Looks like they disintergrate with thew heat. Quote Link to comment Share on other sites More sharing options...
Rich Posted October 3, 2006 Share Posted October 3, 2006 Bingo! Just checked all my coil packs, one plug is completely disintergrated and another wasnt far off being screwed. Got rid of all the crap plastic, slid the pins onto the connectors and filled the plug with silicone. Now running beautifully again. Cheers guys. Are coil pack connectors a common issue? Looks like they disintergrate with thew heat. yes the coil pack connectors are a common fault with a lot of heat getting to then they become brittle and start making a bad connection. Quote Link to comment Share on other sites More sharing options...
supRo Posted October 4, 2006 Share Posted October 4, 2006 As stated already - Coil pack connectors fail easily. Sometimes they even physically look ok but they have damage that you can't see. My J spec runs fine on Ultimate, Tesco 99 and V power. I understood Sainsbury is supplied by BP? Ro Quote Link to comment Share on other sites More sharing options...
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