Zaskar

I have a 99 Camaro with a LQ9 with a Comp Cam Part# 54-458-11 and the supporting mods.


Every since the install been trying chase down a flat spot in the power band, some days the car runs better then others. Its more noticeable if slowly tipping in the throttle. Car gets loud and bogs with loss of power like im pulling a trailer.. from dead stop to about 3500 rpm ,then it takes off

After the install the mechanic told me he had tune so close he didn't feel I needed a Dyno tune. I took it t a Dyno shop anyways , he said on the dyno everything checked ok on the car and he says he squeezed more HP out of it.. 418 HP. I really feel this shop did nothing but mess up my down shifting, down shifted into 2nd before going here

After I got the car back it ran good that day ,then the next day the flat spot came back.and also noticed it had no kick down into 2nd gear when floored from 40 mph.. just goes into 3rd.. Dont trust going back to this dyno

I took it to a performance shop , owner has a modded WS6 he drove car , said it had plenty of power and cant duplicate problem. All looked good on scanner


Picked the car up, was running strong, next day the flat spot came back.

So my question is this,.. Im taking it to another dyno shop and the tuner is one of the best here in AZ with LS engines.. If I have a bad sensor and it shows on the dyno, will he still be able to tune it? I really feel it has to do with the tune...

Have replaced :

O2 sensors

MAF

Throttle Pos sensor

ne

1998 t/a

iTrader: (2)

Did you check fuel pressure? I was always under the impression with those kinds of mods that kind of power you want upgrade injectors and fuel pump

pdxmotorhead

I've had similar symptoms with a plugged fuel pickup screen in the tank. Just a thought...