Hi, 1st post here. I bought an 03 EVO about a month ago with Buschur's stage III kit installed. Couple of issues:

1. Car is not putting out the power it should. GTech posted a max of 258whp from a couple of runs. Car runs smooth and pretty strong. Been talking with Buschur about this - but I'm running out of ideas. I first thought the ECU wasn't flashed...but Buschur has records showing it was.

The only other odd thing - which may be related...

2. During hard cornering (on and off ramps), the car studders - like it is not getting fuel or spark. Only happens when pulling something near .9 Gs +...I've only noticed it on right hand turns, but there aren't too many lefties around my commute. An example would be taking a RH ramp in 2nd gear -40 to 50 mph and something like 5-6k on the tach...it starts studdering until I straighten it the car out. (oh, and all of these are with near full tanks of gas).

I'm thinking it could be a fuel related issue - FPR leaking somehow? Fuel pump issue? But the power is also down in straight line driving...

There are a few checks I'm going to do after vacation - verify the cam timing is set right - verify engine compression...then I'm either going to send the ECU to David for a re-flash, or drive up there for a tune.

Any thoughts?
Thanks in advance.

 

I would say take it to Buschur and have them test drive it or put it on the Dyno. David should be able to isolate what the problem is.

The list of fuel issues could be -

FPR
Fuel Pump or filter

Ignition -

Plugs or gap
Either of the plug wires
Either of the plug coil packs