i was at the dyno yesterday, getting my car tuned to the hondata s200b. everything ran great, until 6500 rpm. i am only running 8 lbs of boost, and i am using the stock map sensor. i have no cel, and have the rev limiter set at 7400 rpm. have checked everything, and can’t find any problems. does anyone have any idea of what is wrong?
What do you mean by “misfire”?
What are your plugges gapped at?
where did you dyno at? Are you using stock injectors? Could be you were detonating.
i am using 440 cc injectors, and am using the ngk 7 series. i dynoed at tempest racing in waldorf, md. the plugs are brand new. sorry for the lack of info. the dyno was great until 6500, and just drops off. i wish i could post my dyno sheet, but my work sux.
sounds like either spark blowout or detonation from timing.
the guy doing the tuning said he kept the timing settings very safe. all my hardware is working great (plugs, wires, distributor, etc.). if it was a spark issue, it would most likely occur earlier than 6500 rpm. i am not running an unsafe tune, everything is just right for being a daily driven car. the only thing i can think it would be would be the stock map sensor.
Fuel pressure dropping off?
What are the plugs gapped to and what is the heat range?
it is the standard gap on that plug. i apologize, but i don’t know what the exact gap is. this plug is 2 steps colder than the stock ones. if the fuel preasure is dropping off, than you would see a decrease in horsepower, not an increase and than all of a sudden nothing, right?
If your fuel pump is not keeping up, you will go lean up top and possibly cause backfires. it personally sounds like a timing issue.
the tuner told me that the afr was excelent all the way through, even when it misfired. i appreciate all of the info. from everyone, i guess i will just have to start replacing/adding stuff until the issue is fixed. maybe i will get an msd ignition, external coil and cap. i’ll start their and see if that resolves the issue.
I don’t know what you’ve tried so I’ll just throw this out there. Have you checked the spark plug gaps? I had a situation a few years ago where I would get a misfire on one cylinder at hifger RPMs. After much tinkering and swearing it tuned out to be a spark plug gap problem.
Also check the ECU itself for error codes. Perhaps it’s got an error code but isn’t triggering the CEL :shrug: