carguysnet

Thanks in advance for any help.I just installed a ls3 376-525hp. GMPP crate engine with a Tremec magnum 6 speed.The wiring harness and matched controller are also GMPP.Has a steady idle and revs fine.Problem seems to be it is slow to return to idle.Not drastic but noticeable especially between shifting gears.If you shift at 2000 rpms there is no drop in RPM's between the gear change.Just doesn't feel right.Also slow to return when parked.Any advice appreciated.

Vexzer

iTrader: (1)

Warranty & tech support from GMMP? You musta spent a tidy sum on that stuff -sounds like an awesome build!

Avanti

Did it come with a manual with a coupon for a free GM idle-check after installation, like my LS3 E-Rod engine? Just curious. Sounds like what it might need.

Gavin Johnson

Usually that's a sign of a vaccum leak

carguysnet

Just spoke with GM Performance.Extremely helpful and sharp.This is the way the ECM is programmed.Slow back to idle.They had complaints about stalling when coming to a stop.Said it may get better with use but will always be there.I asked about changing this function but he said no.
I would like the revs to drop quicker.Does any one have any experience in changing this function?

Jon5212

iTrader: (2)

^^^ Just get it EFI live or HP tuned by someone?

Vexzer

iTrader: (1)

lightweight flywheel!