Thursday, August 14, 2008 - 08:02 am, by: Jason Thornton(Jay9959)
Hi guys Need some help with this misfiring ive read a lot of post about this but mine is different it will rev clean up to 4200rpm and then start to brake down. Idle is great no misfire.
Dose it under load and with out load.
Im using NGK BKR5E spark plugs gap started at 0.7mm misfire started at 3500rpm so i gaped them down to 0.5mm now im getting 4200rpm before it starts to brake down.
I have also tried BKR7E's as well,same gaps as well got same problem.
Both sets of plugs come out black like its not sparking. Or the spark is getting blown out can this be stoped from happening.
I have checked coils all good. Boost is 1bar running boost cut diodes,trim pot set to 4.12 volts.
Could it be the ECU,igniter or bad earths do not have spares to try. Igniter is not getting hot slightly worm.
Thursday, August 14, 2008 - 07:22 pm, by: Daniel Clarke(Dieseltrain)
Try and get a set of good coils and swap em in to try... Make sure you run a minimum 6 heat range plug and move up to a 7 if making big power.. 6 heat range is recommended as a minimum!
Thursday, August 14, 2008 - 07:40 pm, by: Michael Keen(Spoilt)
i agree with daniel, i would run 6 heat range also were in nsw are, you because i know from experience if you live by the coast 7 heat range is fine, but if you live inland and maybe higher altiude then 6 heat range is the go.. cars run a treat up here
Thursday, August 14, 2008 - 09:47 pm, by: Michael Keen(Spoilt)
hey jason where is nsw are you i got a spare set of coil you could borrow to try out if you need to? they not perfect but i pretty sure they work 0438677965 as i wont be back online for a while
Friday, August 15, 2008 - 08:40 am, by: Karl Martin(Karl)
I think theres a few guys on here with a fairly similar problem. There was a thread not long ago on it that may be worth a read as some of the guys listed what they've replaced etc what effect it had. Might save you some money and guesswork.
Sunday, August 17, 2008 - 05:10 pm, by: Jason Thornton(Jay9959)
Ok ive put BKR6E plugs in gap .7mm checked and cleaned all the earths there was no earth going to the head.
Took it for a normal drive let the rev's get up to 4500rpm and there was only the retard of the engine for when it was changing gear so by the sounds of it could have been just bad earths.
Monday, August 18, 2008 - 07:44 pm, by: Jason Thornton(Jay9959)
Hi guy's Gave the car a bit today at WOT and only rev to 3800rpm at 85kmh and 8psi. The speed and rpm,boost would not rise at WOT got a lot popping though like the timing has been retarded badly.
Reving up to this point boost is up to 15psi then drops to 8psi once hit 3800rpm.When i back off the throttle power comes back and boost's over 10psi once again.
Is it possible that it is hitting boost cut even though ive got a boost cut set to 4.15volt.
Plug's NGK BKR6E .7mmgap. Base fuel 36psi and at 15psi fuel is 60psi is this too much fuel pressure at WOT.
Tuesday, August 19, 2008 - 07:36 pm, by: Shane McInnes(Soarin_tt)
It really does sound like coil packs, exact same thing used to happen to me, did you check under the blue rubber seal/boots of the coil pack??? Like i said before it will only take 1 tiny hairline crack to cause that problem.
I could be totally wrong, but just sounds like the coil packs to me.
You can rule out fuel filter, timing, you have a stock ECU so i doubt its that and you could be hitting boost cut at 15psi because 14.7psi is the cut off, but it wont cause it to miss the way your describing, will just feel the car cut off in power then come back on again.
Tuesday, August 19, 2008 - 08:30 pm, by: Jason Thornton(Jay9959)
Hi Shane ye did check under the boots too even went as far as putting het shrink over the stems as well an part over the blue boot. Ye just like the power is limited.
Hi Daniel ill send Jeff an email last time i spoke to Jeff he said his only like around the corner.