3000rpm cutout

Someguy138 · March 16, 2020

1999 GMC suburban k2500 7.4L.

I've ran out of ideas and have hit a wall and would like some advance on what I should do next.ill start with some back story.I bout this suburban knowing it had some problems but it was cheep and I need a bigger tow rig.Bought it knowing it needed a lower intake gasket and the fuel pressure regulator vacuum line was broken and needed replaced and it would also "cutout"or "missfires" when it got to 3000rpm.Has never set a service engine light either.

Things I've replaced/tested

Function of the service engine light.Works and will throw the correct codes when unplugging sensors.

Compression check 145-150 on all 8

Lower intake and upper intake gasket.

Fuel pressure regulator and vacuum line.

Injections.

Distributor, plugs,wires,cap,roter,coil and module,cam timing set to 0*

Both upstream 02s.

Fuel filter,fuel pump volume and pressure.

MAF,map,tps,coolant sensor.

Plugged cats.

Still get the cutout at 3000rpm and it doesn't matter if it's in park or while driving.Other then that it runs great.I also have access to a good snap on scanner and have checked live data feeds and have noticed that when in park or out of gear the LT fuel trims read rich on both banks at about -10 to -15 but as soon as it's in gear it's normal around 0....not sure if that matters.Any advice on where to go next would be greatly appreciated.Starting to think a PCM problem but maybe I'm missing something.