Hondata

Guys i need some help here.

What maybe the cause of a missfire at 6800rpm?

Plugs are showing no signs of detonation or heat issues.
Fueling a little rich but not anywhere near enough to cause this issue.
Timing changes not making any difference, tried +- 3 degrees with no difference ( keeping close eye on spark plugs ).

I cant see anything on the datalog that may explain whats happening, but i could do with an experts opinion.

The only thing noticed is that the alternator isnt working and the battery voltage is very low, but even with a fresh battery reading 12v the problem was the same. I understand that with the alternator working correctly the voltage would be over 13v but would this make a difference/ cause this issue?

Please note, vtec at 3500 and just started tuning the high cam, hence the wacky AF below 5500rpm, only made a couple of runs to try and rectify this issue. Let off immediatly after missfire.

Ideas guys, im stumped.

ps, im not saying this is a problem with s300, just looking for some help identifying the problem with the datalog.

Craig

The datalogged battery voltage is below 10V. The battery voltage needs to be at least 13.8V - even with a freshly charged battery but no alternator you'll get misfires.

Thats what i thought, thats what i was hoping too, thanks mate.

I just thought that if it was a voltage problem then it may happen more often than just high revs/load?

I will report back when the alternator has been changed.

Craig