sorry if this has an obvious answer.

just put a ported blower and LS4 tb on my LSJ and idle is crazy.

on startup, it has a 10-20 seconds of fluctuating 700-1500 before it settles at 1k,
then half the time when I hit the clutch to roll into a stop, it idles at 2k.

RPMs in third gear (and probably the rest) seem higher at the same speed I drove before install.
plus the gas pedal is touchy as hell.

am I right to assume that a tune would fix these kinds of problems? or did I do something wrong with installation?
I was leery on installing that boost actuator and the little throttle it hooks up to but the rest seemed to go smooth.

 

there are some changes that have to be made in the tune to run the ls4 throttle body. there is one box (idle scalar) that needs to be changed just to get it to idle properly. i also had to play with a few other settings to get it to idle down the way i wanted.

 

what else did you tweak if you remember?

also, do you think it'll hurt the car to drive it once or twice before I get someone to modify the pcm?

 

honestly you will not be able to drive the car with the LS4 until the scaler changes are made. The additional air will require MAF retrim

 

already drove it, barely made it but I'm taking it out until I find a tuner around here.

never heard of needing a MAF retrim though.

 

i could see re tuning the maf table to get things perfect again, however i cant see the bigger throttle body throwing the fuel trims off by more than a couple %