2001 DF70 wont go over 3000 rpms


Sep 6, 2023
I have a df70 that I tore down and cleaned out all the water jackets. I replaced all of the gaskets and head gasket and put it all back together. The motor after putting back together has 140lbs compression on all cylinders. New plugs, vst gone through, throttle body cleaned and all electrical reinstalled. Now when I push the throttle it only will go to 3000rpm. I have tested the neutral safety switch in the throttle box and on the motor. After starting the motor I unplugged the NSS and still nothing.
I have no beeps or lights on the dash until I unplug and of the connectors on the ECU. I had someone attempt to hook it to the Suzuki computer and it would not even show that it was connected. All sensors have been tested for resistance and all check out.
Only thing that I can figure is the ECU has gone bad.

I have tested the voltage to the fuel pump and get 12v when key on and 0v when key off. I read somewhere that the voltage should only last for a few seconds but not sure how to determine that.

Any help is greatly appreciated.