Chevrolet Repair: engine cutting out during hard accel only in overdrive, throttle position sensor, fuel pump relay

Question
i have a 1997 Z71 with the 350 vortech and 4L60E i have recently changed the fuel pump, fuel filter, and fuel pump relay.. At wide open throttle and even at half throttle the engine will cut out and then surge.. as if its not getting enough fuel.. but in 1,2,Drive, Nuetral, and Reverse, i dont have this problem.. fuel PSI at start up is aprx 60psi.. Any ideas on what this could be?

Answer
Hello Eric,
See what the fuel pressure is when it cuts out. It should remain at the 60.
If it drops, there is a fuel supply or pressure control problem.
But if the pressure stays at 60, then I would first suspect the TPS,(throttle position sensor). It can be bad, and still not throw a code.
If the EGR valve is opening at that same time, it could do the same thing, but the EGR should throw a code, and light the engine light.

I don't have a manual....is 60 about what that truck calls for?

But if the pressure is correct, and stays there, when you open the throttle, you manually allow much more air in, and if there is not a coresponding signal from the TPS, there won't be the appropriate amount of fuel to go with it, and it will be very lean. The O2 sensor then might catch the lean condition and attempt to correct it, but we are getting deeper than I like to be.

Van