I have a 1995 12 valve in a 1998 Chevy k3500. Rebuilt engine myself. Has 5x.011 injectors vco from DAP . Hw1c turbo.. I have the engine set at 14.5 degrees timing. Has a brand new OFV fuel pressure at idle is 25 PSI and seems about 30-35 under rpm. I dont have an in truck guage to see what it is under a load.

My problem is as I roll into the throttle anything over 2500 rpm the motor loses power blows white smoke and pops. I have the 4k governor springs in it and it won't go over 2800. Runs great below that and smooth idle instant start up.

Need some ideas where to go next

 

Ok so I was mistaken on fuel pressure, it's about 22 at 2200 if I pinch off the return it will rev out to 2800 before I left off. So it's a fuel supply issue. Pinching return makes it go to 80 psi very fast so I'm thinking the lift pump is fine. It's a brand new overflow valve but looks like it's bad