Right, mapped this guys car a while ago, and it has developed a misfire in 1st at around 6000 RPM in first gear only. The fueling goes lean to about 13.5:1, but in 2nd & 3rd it's at 11.9/12.0:1 which is much more like it.
The IDC is the same in all gears, the load is the same, the RPM is the same and it's using the exact same part of the map, but for some funny reason it's rich @ 2500 RPM (10.7:1), then lean at 6000 RPM onwards, where as in other gears it's fine all the way through.
Any one got any ideas? Logs attached.
Strange lean running/misfire only in first gear??
Moderator: Matt
Re: Strange lean running/misfire only in first gear??
post your bin file...that will help us diagnose quicker so that way we can maptrace on the map(s) with your log file.
Re: Strange lean running/misfire only in first gear??
At work just now, will post up the BIN when I get home.
Re: Strange lean running/misfire only in first gear??
As promised....
- Attachments
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- gs13.bin
- (32 KiB) Downloaded 203 times
Re: Strange lean running/misfire only in first gear??
See what you are saying here
Disagree that its accessing the same part of the map (evident by maptrace) but here the injection pulwsewidth is low (relatively) about 6.36ms but that is before batch mode, hence the AFRs (really its about 12.6ms injection time taking that into account)
The TP reading is lower but you will notice once TPS=4.12 volts as per picture that the injection shot up. I think this is acceleration increase accessing the last column on the map
Would be a good idea if I could simulate this for the maptracing (since you dont see this) so you get a better idea what is going on in the background
I think its accessing 27/28 perhaps @ 2000-2400rpm? You can check by pulling those values leaner
Disagree that its accessing the same part of the map (evident by maptrace) but here the injection pulwsewidth is low (relatively) about 6.36ms but that is before batch mode, hence the AFRs (really its about 12.6ms injection time taking that into account)
The TP reading is lower but you will notice once TPS=4.12 volts as per picture that the injection shot up. I think this is acceleration increase accessing the last column on the map
Would be a good idea if I could simulate this for the maptracing (since you dont see this) so you get a better idea what is going on in the background
I think its accessing 27/28 perhaps @ 2000-2400rpm? You can check by pulling those values leaner
- Attachments
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- herman_gary_ecu.JPG
- log playback
- (235.75 KiB) Downloaded 2640 times
Re: Strange lean running/misfire only in first gear??
Cheers for the advice Matt, but when I said it was using the same part of the map, I was meaning past 6000 RPM in 1st, 2nd & 3rd it used the same part of the map, but for some strange reason it was lean in first gear only.
I knew it wasn't using the same part of the map lower down the revs where it goes rich at ~2500 RPM. My main concern is the 13.5:1 AFR higher up the revs which is in turn causing the car to misfire.
Any ideas about that?
Cheers!
I knew it wasn't using the same part of the map lower down the revs where it goes rich at ~2500 RPM. My main concern is the 13.5:1 AFR higher up the revs which is in turn causing the car to misfire.
Any ideas about that?
Cheers!
Re: Strange lean running/misfire only in first gear??
Not sure on that one