Hey guys I got a problem Im having some trouble tracking down. I have been tuning the car up lately increasing the boost and dialing in the AFR. Anyways the car was still running 2" pipe on the hot side of the intercooler so upgraded that to 2.5" and ever since then the car has a misfire above 20psi. As soon the turbo spools in 3rd the car starts misfiring and bucking until I let off. The fuel is low 11s, timing is still low around 12* so I figured it was blowing out the spark. Check plugs and regapped them to .024". Didn't fix the problem, pulled some more timing up top and nothing changed. Im still thinking its blowing out spark so tmrw Ill try lowering the boost back down a couple psi and see if that helps any. Im still on the stock coil pack maybe thats not strong enough at this power level.
Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim
#108537, "RE: Misfire at high boost" In response to Reply # 0 Feb-21-11 03:07 PM by bullettdsm
Originally posted by SilvrEclips Im still on the stock coil pack maybe thats not strong enough at this power level. The car is pushing a little over 400bhp.
Curious. I lost the stock coil pack (and the MSD coil pack) at a little over 500whp at 24lbs on a bw366 with 10.5 comp (as I recollect). I ended up using the Screamin' Deamon coil for another 5lbs to 567whp. My plug gap at that time was .018.
So it is possible, but it seems a little low for a power threshold. Maybe the coil is getting weak? I take it you're running a 3 bar. It is possible that she is malfuntioning. I did have a 3 bar that would only go to the mid 20's.
Captain Caveman
96 RS Turbo 11.414 @ 119.62 MSNS, Crower 2 NA cams, BW366, 10.5 comp, UDP, 60mm TB, W/A intercooler, 3.55 tranny 567.9whp 430tq 97 RS NA 13.188 @ 103.87 MSnS powered 12.5 comp, Crower 3's and 219.4whp with 175tq 98 RS DD 12.5 comp on stock ECU, LTH, Crower 2's, Koni, GC, Hypercoil, DG hats 99 OZ 5sp Stocker 15.856 @ 85.97 99 GS stocker auto 17.7@77mph!
#108538, "RE: Misfire at high boost" In response to Reply # 3
Originally posted by bullettdsm
Originally posted by SilvrEclips Im still on the stock coil pack maybe thats not strong enough at this power level. The car is pushing a little over 400bhp.
Curious. I lost the stock coil pack (and the MSD coil pack) at a little over 500whp at 24lbs on a bw366 with 10.5 comp (as I recollect). I ended up using the Screamin' Deamon coil for another 5lbs to 567whp. My plug gap at that time was .018. So it is possible, but it seems a little low for a power threshold. Maybe the coil is getting weak? I take it you're running a 3 bar. It is possible that she is malfuntioning. I did have a 3 bar that would only go to the mid 20's.
yea, after what bullett said, don't go to .015 as i said earlier. start at .018 if .020 doesnt do it. small steps.
Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim
#108549, "RE: Misfire at high boost" In response to Reply # 8
Just another data point for you. When I started raising my boost, I would get a misfire at peak boost. Increasing my dwell eliminated the misfire, without reducing spark plug gap. I am using 4.5 ms on internal Fairchild ignition drivers.
#108550, "RE: Misfire at high boost" In response to Reply # 9
Increase running dwell up to 4.0ms with the plugs gapped at .024 still. Boost is up to 23psi and not blowing out spark yet. That seems to have helped. Ill probably up it a couple more psi when I get the car tuned a little more. Thanks guys
Outside of Corona: "That sucks, peace out..." (jamie walks away)... "Sweeet, what we doin?" -Zac Tim's garage (prior to motor install): "Im gonna smoke real quick, that way if you fuck up I am already nicotined up" -Tim
