So I have a Gen 1 motor in a mini sandrail. I ran a NA motor for the last 12 years. Over a year ago my bottom end went out so I picked up a new (used gen 1) with a turbo kit. Not sure the kit brand. pretty sure it's custom setup. Anyways. I'm running stock ECU with PC5. I got it in the car and started it up, got it on the dyno for tuning got started and we heard a terrible squeal. I tore the valve cover off and found one the cam had destroyed one of the journals and the head was ruined. I tore into the motor to find no oil gear had been installed. So I called the guy I got it from. He tore it down to check that nothing else was hurt and we pulled the head form my old motor to get it back running again. But now it has a new issue. When I throttle up it's like there's a governor around 5600 rpm just before the boost comes on. We plugged the computer in to the PC5 and found that around 5600 rpm it reads 0 rpm. So of course it cuts fuel then drops to where it reads rpm again and then kicks fuel in and revs back up to 0 rpm and you get the picture. We leaned it out real good right before that to get it to jump past that rpm point and it reads again and the turbo spools and she's a rocket. So the issue is just at that point. Any ideas? I can't find anyone else ever having this issue. I know a guy at dynojet so I'm going to have the PC5 tested but just wondering if there's anything else I should look at? I guess it could be in the ECU maybe?