Misfiring at high boost
Registered User
Joined: Nov 2007
Posts: 182
Likes: 0
what is your A/F like in that area? I had the same issue so I bumped my old thread up for you to help out.
[/quote]
somewhere around 10.5, please send me the link of your old thread, thank you thank you.
Community Organizer
Joined: Jun 2007
Posts: 31,070
Likes: 566
Originally Posted by donaldmejr' timestamp='1320892823' post='21143935
[quote name='8940rpm' timestamp='1320890497' post='21143858']
[quote name='donaldmejr' timestamp='1320874391' post='21143092']
is it miss firing during the pulls or during light throttle high rpms?
[quote name='donaldmejr' timestamp='1320874391' post='21143092']
is it miss firing during the pulls or during light throttle high rpms?
what is your A/F like in that area? I had the same issue so I bumped my old thread up for you to help out.
[/quote]
somewhere around 10.5, please send me the link of your old thread, thank you thank you.
[/quote]
Yeah that's too rich at partial throttle, and with it being at high rpm your cylinders are loading up. I bet if you leaned it out in that area by a point at least, the problem will go away. Maybe your tuner was tuning for a higher throttle load then was actual on the street. And the transition between this open loop/closed loop fueling needs to be recalibrated. But just a guess.
Registered User
Joined: Jul 2003
Posts: 1,461
Likes: 3
From: Mill Creek
Originally Posted by Cody Strife' timestamp='1320957606' post='21146307
This may sound stupid, but I've experienced the same thing, but only when my fuel drops to 1/4 of a tank. I don't get that, I really don't...
Registered User
Joined: Aug 2009
Posts: 876
Likes: 0
From: Richmond, VA
Originally Posted by JoeyBalls' timestamp='1320886877' post='21143697
thx guys, im using NGK copper plugs(7173), heat range 8's.I'm going to put new ones in, and get them gapped appropriately 
Registered User
Joined: Aug 2009
Posts: 876
Likes: 0
From: Richmond, VA
Hello people. So the car runs really nice and strong at 12psi, however I have noticed lately, that at higher boost levels (car was tuned by Evans at 16.5 psi, tends to hit 17-18 in this nice cool weather, no big deal). Anway so on the highway I did some high boost pulls and the car misfired pretty badly. I do have 98 Octane in it, and the logs show no knock, or pullng of timing so what could it be? I have 110,000 miles on the original coil packs. Car has been boosted since 60k. I also run water Meth with may or may not contribute?
Also, interestingly enough, it sometimes does not do this during a high boost pull if I have been beating on it and the EGTS are in the 1,100-1,200 range. Basically its like if I do a few pulls back to back and heat up the turbo (egts etc) it is less likely to misfire)
I had to pull on a modded Audi RS4 today in low boost, took slightly longer than it should have
Also, interestingly enough, it sometimes does not do this during a high boost pull if I have been beating on it and the EGTS are in the 1,100-1,200 range. Basically its like if I do a few pulls back to back and heat up the turbo (egts etc) it is less likely to misfire)
I had to pull on a modded Audi RS4 today in low boost, took slightly longer than it should have
Thread Starter
Joined: Jan 2008
Posts: 9,570
Likes: 3
From: New Jersey
UPDATE
I am waiting on new 7173's so in the mean time I put in the NGK V-Racing 7405 (part number R5672A-9) Theses are my plugs for the Race Gas tune, and the misfiring is gone and with the slightly higer octane and cooler temps, the car pulls noticeably harder than before. The plugs were probbaly going south for a while
PS I had to hook my exhuast back up, lately the fumes from the Open Downpipe are actually starting to hurt my throat I will just use the electrical cutout for now and run the open downpipe for the track or on Q16. I probably won't lose much HO if any, however the main reason for me running an open downpipe was the reduced EGT's (made a HUGE diff) For example after a pull with the exhuast hooked up it would hang out around 1200-1300, with the open downpipe WOT it barely breaks 1,100's and if it does it backs down to 800-900 within a minute!
I am waiting on new 7173's so in the mean time I put in the NGK V-Racing 7405 (part number R5672A-9) Theses are my plugs for the Race Gas tune, and the misfiring is gone and with the slightly higer octane and cooler temps, the car pulls noticeably harder than before. The plugs were probbaly going south for a while
PS I had to hook my exhuast back up, lately the fumes from the Open Downpipe are actually starting to hurt my throat
I will just use the electrical cutout for now and run the open downpipe for the track or on Q16. I probably won't lose much HO if any, however the main reason for me running an open downpipe was the reduced EGT's (made a HUGE diff) For example after a pull with the exhuast hooked up it would hang out around 1200-1300, with the open downpipe WOT it barely breaks 1,100's and if it does it backs down to 800-900 within a minute!
Thread Starter
Joined: Jan 2008
Posts: 9,570
Likes: 3
From: New Jersey
^ Yea. Its f@#king loud, especially when you hit it and their is either a car or wall near you, lol. The fumes seem to be much worse in the winter, dunno why. The car def spools quicker with an open downpipe, also makes it sound like a cammed Neon, lol. I will run an open downpipe when I run Q16, but for the rest of the winter I am going to just use the electrical cutout.