Misfire at high boost+high RPMs
10-05-2005, 09:02 AM
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Misfire at high boost+high RPMs
Setup is a Z6 block, Y5 head, 450cc's w/Uberdata. T3 .48/.60
Well I'm having a hell of a misfire and it's robbing the **** out of my horsepower.
I used to run 7 psi of boost and have no problems. I upped the boost to 9-10 psi and now it pulls harder, but at about 4000-4500 RPM it starts to misfire and I just lose power. Ocassionally I can get a full pull without misfire and it just ******* rips, but most of the time I get the misfire. I am running uberdata and have tuned my map as well as I can with the misfire, when it does misfire I get erroneous lean readings so I can't really tune that. I am confident that this problem is not with my map.
I don't think it is plug wires because they look just fine and don't misfire under any other conditions than high boost+high RPM.
Thought about it being the distributor cap, I actually had an almost new distributor that I was using on my old setup working perfectly. I just swapped that one over and I still have the problem.
I reused the spark plugs from my old setup, NGK BKR7E gapped at .030, I also tried .028. They did get a little black around the edges (not the electrode) from when I was running rich on the basemap but I don't think that should make a difference as long as they are gapped right... or would it? I have ordered a new set of plugs just incase, because that is the only thing I can think is wrong besides....
My base timing. I don't have a timing light and haven't set my base timing. Could this cause a bad misfire if it's too advanced or retarded? I am going to rent a timing light to check that.
Help !!
Well I'm having a hell of a misfire and it's robbing the **** out of my horsepower.
I used to run 7 psi of boost and have no problems. I upped the boost to 9-10 psi and now it pulls harder, but at about 4000-4500 RPM it starts to misfire and I just lose power. Ocassionally I can get a full pull without misfire and it just ******* rips, but most of the time I get the misfire. I am running uberdata and have tuned my map as well as I can with the misfire, when it does misfire I get erroneous lean readings so I can't really tune that. I am confident that this problem is not with my map.
I don't think it is plug wires because they look just fine and don't misfire under any other conditions than high boost+high RPM.
Thought about it being the distributor cap, I actually had an almost new distributor that I was using on my old setup working perfectly. I just swapped that one over and I still have the problem.
I reused the spark plugs from my old setup, NGK BKR7E gapped at .030, I also tried .028. They did get a little black around the edges (not the electrode) from when I was running rich on the basemap but I don't think that should make a difference as long as they are gapped right... or would it? I have ordered a new set of plugs just incase, because that is the only thing I can think is wrong besides....
My base timing. I don't have a timing light and haven't set my base timing. Could this cause a bad misfire if it's too advanced or retarded? I am going to rent a timing light to check that.
Help !!
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10-05-2005, 02:23 PM
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Re: (BlackDAy)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BlackDAy »</TD></TR><TR><TD CLASS="quote">check your timing, i would retard a little too.</TD></TR></TABLE>
Pointless to retard timing at the distributor, I have a linear retard going through Uberdata.
Pointless to retard timing at the distributor, I have a linear retard going through Uberdata.
10-05-2005, 08:07 PM
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Re: (D@nnY)
Sounds like a possible weak coil, 7-9psi shouldn't be blowing out the spark with a .028" gap, take 5 minutes to swap your coil with a friend and eliminate that possibility.
10-06-2005, 12:25 PM
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Re: (Jizzmaster Zero)
get an MSD and external coil setup. It will eliminate all misfires. Your stock internal coil is no match for a boosted setup. Take this advice I have been there.
10-06-2005, 12:45 PM
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Re: (cul8tr)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cul8tr »</TD></TR><TR><TD CLASS="quote">get an MSD and external coil setup. It will eliminate all misfires. Your stock internal coil is no match for a boosted setup. Take this advice I have been there.</TD></TR></TABLE>
yeah right. Lots of people have run stock ignition hondas to 500 whp + This 200 hp car is not going to need a different ignition system. Have you set your base timing recently? I"m not sure what the differences of putting the y5 head on there are but maybe you should try advancing the timing a little and seeing what happens. If the timing is too retarded at the dizzy uberdata isn't going to fix it, and the car will run like crap. Just a thought.
yeah right. Lots of people have run stock ignition hondas to 500 whp + This 200 hp car is not going to need a different ignition system. Have you set your base timing recently? I"m not sure what the differences of putting the y5 head on there are but maybe you should try advancing the timing a little and seeing what happens. If the timing is too retarded at the dizzy uberdata isn't going to fix it, and the car will run like crap. Just a thought.
10-06-2005, 12:48 PM
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Re: (nonvtecD)
You might want to check your Dizzy, if it has high miles on it the shaft might have play, causing it to misifre at high rpms. i dont think its a timing issue. my first guess would be to big a gap on the plugs. but most likely its the distributor shaft play or a weak ignition coil or pickup in the Dizzy.
10-06-2005, 01:00 PM
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Re: (Jizzmaster Zero)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jizzmaster Zero »</TD></TR><TR><TD CLASS="quote">I just replaced the whole distributor with a known good one.</TD></TR></TABLE>
Did you try swapping wires? Changing plugs?
Did you try swapping wires? Changing plugs?
10-06-2005, 02:31 PM
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I ran the same plugs for like 5 years, stock Honda plugs, ran them through rich basemaps and limp mode drives, never gave me one problem. I don't think it's your plugs but... worth a shot I guess.
10-11-2005, 04:05 PM
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Re: (nonvtecD)
Back up
Just put new plugs in today (BKR7E gapped at .030") and the same thing is still happening. It starts misfiring at kinda acts like a rev limiter at 4500-5000 rpm. Sometimes it will rev a little higher.
I am totally clueless at this point.
Just put new plugs in today (BKR7E gapped at .030") and the same thing is still happening. It starts misfiring at kinda acts like a rev limiter at 4500-5000 rpm. Sometimes it will rev a little higher.
I am totally clueless at this point.
10-11-2005, 05:15 PM
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Re: (Jizzmaster Zero)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jizzmaster Zero »</TD></TR><TR><TD CLASS="quote">Back up
Just put new plugs in today (BKR7E gapped at .030") and the same thing is still happening. It starts misfiring at kinda acts like a rev limiter at 4500-5000 rpm. Sometimes it will rev a little higher.
I am totally clueless at this point.</TD></TR></TABLE>
I'm having the same problem too.
But I got a msd ss and it's still misfiring.
I'm clueless what to do since I tried almost everything I could.
my problem thread
https://honda-tech.com/zerothread?id=1399187
Just put new plugs in today (BKR7E gapped at .030") and the same thing is still happening. It starts misfiring at kinda acts like a rev limiter at 4500-5000 rpm. Sometimes it will rev a little higher.
I am totally clueless at this point.</TD></TR></TABLE>
I'm having the same problem too.
But I got a msd ss and it's still misfiring.
I'm clueless what to do since I tried almost everything I could.
my problem thread
https://honda-tech.com/zerothread?id=1399187
10-11-2005, 06:12 PM
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Re: (BoostedAsian)
i was having the same problem also.. it started doing it at the track..it would hit either 5k or 6k and feel like it was bouncing off the rev limiter.. at first i thought it was timing but checked out fine.. i changed out the plugs.. it stopped the high end misfire, but still had the 3rd gear 5-6k rev limiter.. thought it was the cap and rotor.. changed that and same ****..
at the track i was doing 13lbs and on the street 15lbs.. i ran 15lbs for about 2 months with no problems.. thought it was my map starting to take a ****.. wrong.. it was my uberdata map.. i originally had it tuned for 12lbs and bumped it up to 15 lbs and it ran fine for a month and then started shitting on me at the track.. finally i turned it down to 12lbs again and it hasnt done it since.. so i guess a new tune is in order and i guess i'll finally use my 3 bar
.. turn down the boost a few lbs and see what happens..
at the track i was doing 13lbs and on the street 15lbs.. i ran 15lbs for about 2 months with no problems.. thought it was my map starting to take a ****.. wrong.. it was my uberdata map.. i originally had it tuned for 12lbs and bumped it up to 15 lbs and it ran fine for a month and then started shitting on me at the track.. finally i turned it down to 12lbs again and it hasnt done it since.. so i guess a new tune is in order and i guess i'll finally use my 3 bar
.. turn down the boost a few lbs and see what happens..
10-12-2005, 08:47 AM
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Re: (eli_vang)
Well yea, if I run at 7 psi there is no problem. But 7 psi is too slow
I know I will have to slightly tune the areas of the map that are above 7 psi now that I'm running 9 or 10, but my AFR is about 11.7:1 right when it happens. What's the deal with that?
I know I will have to slightly tune the areas of the map that are above 7 psi now that I'm running 9 or 10, but my AFR is about 11.7:1 right when it happens. What's the deal with that?
10-12-2005, 11:42 AM
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Re: (ILLICON5000)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ILLICON5000 »</TD></TR><TR><TD CLASS="quote">you just answered your own question. you are running uberdata and I bet you it's *** tuned</TD></TR></TABLE>
STFU, you know nothing.
Tuning with an Innovate LM-1
STFU, you know nothing.
Tuning with an Innovate LM-1