EFIDynoTuning Forum

Working on my tune some more. VE table is dialed in. I'm struggling with transient fuel (tip-in or accelerator pump on a carb). When I goose it, the wideband very momentarily goes offscale lean then just as fast swings rich, down to 11:1 or so before coming back to stoich. As a result, the truck bucks a little bit if you stab it.

I know there's a parameter to adjust that would correct this, but I'm having trouble figuring out which one. Changing FN1303 (accel enrichment) by up to 50% plus or minus doesn't have a noticeable effect. Do I need to try FN1321? Is there another parameter to try?

thats a misfire from flooding out from too much accel enrichment

sounds like you need to reduce it significantly

Hmmmm. I hadn't considered that. Like I said, I did try messing with FN1303 significantly in both directions and it had no discernable effect on anything.

Just out of curiosity, what's the difference between FN1303 vs FN1321 with respect to how they affect function of the engine?

accel enrichment is based on throttle movement

transient is based on load changing