zrater

im getting some bucking with no tps in drive coasting at 15 to 30
mph, is this to much timing or maby throttle cracker table.
just doesnt feel right. doesnt do it in od, but drive. u feel it
alot.. thanks

SSpdDmon

iTrader: (10)

Is your car still running the stock head/cam setup?

zrater

yes all stock but lid. tune has been change alittle but not much..

zrater

if dfco is shut off could this cause this..

SSpdDmon

iTrader: (10)

If you haven't changed anything other than add a lid, then there's not a whole lot that should be changed in the tune. Maybe a little fueling/timing adjustments and some trans adjustments. But other than that, things should pretty much be left stock. I'd suggest putting everything else back to stock (including DFCO).

VinceTrifecta

This usually has to do with the engine running rough with the torque converter clutch is locked up. My Impala SS had a big problem with this after I cammed it, so I raised the TCC lockup points.

Additionally, you feel it more in 3rd gear (D) because the gear ratio is lower.

You can test the theory by raising your TCC lockup speeds higher, or temporarily disabling TCC lockup altogether and see if it gets better. Or you can use the VCM controls feature of the HP Tuners scanner to disable TCC lockup.

If this proves to be the issue, the big question is, though, why is a relatively stock car running rough under those conditions?