Went datalogging tonight and had the most werid result that I would like to share...

Set up is HRC stage 3: JE/Eagle, SFMU, ML, and 270cc at 5psi actuator.

all other things normal:
Coolant: 198-203*
Intake air: approx 100* +/- 5
Short trem fuel trim: +/- 3% (toward zero)
Long term: -21%
EGT at WOT 1500
EGT at crusing 1100-1200

At WOT off the launch, I get this weird fuel cut problem. It mainly occurs between 4K-5K RPM. I know it is not the ML because it was just cleaned.

I was fortunate enough to capture this little fiasco on my cheap RRE logger program.

WOT O2 voltage is 0.94-0.98 (a bit rich) across. However at the point of stuttering, it dropped to 0.135 and pick up again 0.92.

Ignition timing ranges from 16-19* under WOT, but at the point of stuttering it is a consistant 16.5*.

So my question is WTF is going on...there is no timing pulled at fuel cut, but obviously there is a lean condition...

Anyone care to comment. I wish I know how to post the graph...

Perhaps its a rich condition instead of lean. Long term fuel trim is at -21%. This is at idle, I suppose. It may get worse at other operating points. Perhaps you run way rich for a second (hence the super low O2 voltage).

If you could get the graph up on your screen, you can hit the "print screen" button and paste the screen shot into MS Paint. Then the screen shot can be edited and saved for posting to the web. Thats what I do anyway.

Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire