Jim_1979 Posted August 19, 2008 Share Posted August 19, 2008 Running a Jspec Supra BPU with UK Turbos (if it makes a difference). Also recently noticed the first cat is still in place (the one right at the turbos). Apart from that, running: Blitz Nur Spec mid cat removed walbro pump FCD Greddy Profec B Spec II I had a missfire issue on high boost 1.15bar so I changed the plugs to some NGK copper plugs gapped to 0.7mm. This didn't resolve the missfire issue. I then replaced all the coilpack connectors. All good... it seemed to sort the problem out. The plugs were changed about 350miles ago, clips 300miles ago. The missfire really only happens on high boost at full WOT, about 5 to 6K rpm. It feels like a VERY rapid hesitation as if it's struggling to accelerate. The car seems fine on low boost 0.8bar. Only noticed it hesitate once. So... what now? Surely the plugs can't be duff as they aren't old. The clips have been changed already. Should I go with the more xpensive irridium plugs? People on here said the plugs I went for should have been fine etc. The point I'm getting to is that I don't want to spend shedloads on new coilpacks if they're not needed. Also, is there anyway to test the coilpacks as for all I know if this is the problem, it could only be one that's duff? How long do coilpacks generally last for? thanks Quote Link to comment Share on other sites More sharing options...
Homer Posted August 19, 2008 Share Posted August 19, 2008 Do you have an AFR or EGT gauge? If so, what sort of readings are you seeing at max boost? The coil pack clips, if renewed should last for years and massive mileage. Which model of spark plugs did you use? The BCP7** grade ones at a 0.7mm gap are absolutely fine for BPU, very, very tried and tested by hundreds here. The next point of call would be the coil packs themselves. Quote Link to comment Share on other sites More sharing options...
Jim_1979 Posted August 19, 2008 Author Share Posted August 19, 2008 No mate, no AFR or EGT gauge. Only boost gauge. Why do you ask? Yeah, I've got these plugs BCPR7ES. So the coilpacks then?? God damn. lol. Is there anyway to actually test them? Like I said, I don't want to buy all 6 if only 1 or two are dead. Quote Link to comment Share on other sites More sharing options...
Homer Posted August 19, 2008 Share Posted August 19, 2008 An AFR gauge would show if it's a lean burn causing the misfire, but hopefully its not that!! There is a way of testing them, but I can't remember, if no one else replies I'll take a look at the service manual later. Quote Link to comment Share on other sites More sharing options...
Jim_1979 Posted August 19, 2008 Author Share Posted August 19, 2008 Lean burn? What exactly is this and how would it be caused? I assume simply by the car running lean? Surely it shouldn't be the case with the walbro etc? Quote Link to comment Share on other sites More sharing options...
Jim_1979 Posted August 20, 2008 Author Share Posted August 20, 2008 How long do coilpacks normally last? Quote Link to comment Share on other sites More sharing options...
Angarak Posted September 1, 2008 Share Posted September 1, 2008 (edited) Lean burn? What exactly is this and how would it be caused? I assume simply by the car running lean? Surely it shouldn't be the case with the walbro etc? *bump* I think I have a lean burn issue - my car hasnt been driven in the last 2 weeks so took it for a spin today, normal residential driving, then onto a dual carriageway for a little 1.1bar blast upto 80 leps then back down to normal leppage and back onto normal residential roads and called off at a mates house. Mate wasnt in, so back in the car, start it and its idling very low with my AFR showing lean off the gauge. Rev the engine and the AFR shows it going rich but back to off scale (lean) on idle around 300rpm. Drove home off boost via residential roads, car seemed to drive fine so wasnt sure if my AFR sensor was buggered, but with it idling so low I thought maybe a plug issue or worse - my walbro has developed a fault. Waiting for it to cool down now so I can whip the plugs out and check them (theyre either IK22's or IK24's I think)... Edited September 1, 2008 by Angarak (see edit history) Quote Link to comment Share on other sites More sharing options...
ADD Posted September 1, 2008 Share Posted September 1, 2008 Jim, i had exactly the same symptons as you bud, replaced the coil pack connectors (worked fine for a bit) then plugs IK24's (no change) but then done the coilpack's themselves and replaced plugs with HKS S40i's....now at 1.4 bar its running absolutely perfect! Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted September 1, 2008 Share Posted September 1, 2008 You are sure its a misfire you have and its not detting? way too rich can also cause a misfire, but lean is more likely the cause. Quote Link to comment Share on other sites More sharing options...
merckx Posted September 1, 2008 Share Posted September 1, 2008 So the coilpacks then?? God damn. lol. Not necessarily,new ones didn't cure my misfire. Have you checked for fault codes? Quote Link to comment Share on other sites More sharing options...
Jim_1979 Posted September 1, 2008 Author Share Posted September 1, 2008 You are sure its a misfire you have and its not detting? way too rich can also cause a misfire, but lean is more likely the cause. Why would it be detonation? Car has walbro pump and only 1.15bar. No reason why it should be running lean surely? It also did work fine for a little while after clips were changed. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted September 1, 2008 Share Posted September 1, 2008 Why would it be detonation? Car has walbro pump and only 1.15bar. No reason why it should be running lean surely? It also did work fine for a little while after clips were changed. Just wanted to be sure you where sure, as at high boost and those sort of RPMs if you had a dodgy injector or pump it could run lean, and you're not running an AFR or EGT gauge, have you tried checking the crank position sensor? Quote Link to comment Share on other sites More sharing options...
Jim_1979 Posted September 1, 2008 Author Share Posted September 1, 2008 Nah mate, not tried anything other than the clips and plugs. Clips did sort the situation out for a little while. Quote Link to comment Share on other sites More sharing options...
Jim_1979 Posted September 14, 2008 Author Share Posted September 14, 2008 Fitted some coilpacks this evening and job's a good'un. All sorted and boosting like a crazy mofo again! Quote Link to comment Share on other sites More sharing options...
tango Posted September 17, 2008 Share Posted September 17, 2008 how much are the coil pack cost you? I had the same sympton, but just change some top spec plug, its sorted. cheers Quote Link to comment Share on other sites More sharing options...
Jim_1979 Posted September 17, 2008 Author Share Posted September 17, 2008 £75 from a member on here. Quote Link to comment Share on other sites More sharing options...
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