starts fine cold.runs good till it gets hot.then seems to miss or have half the power.also hard to start after driven.fuel pressure reads 40 key on then drops to 0 fast.engine idles stays at around 32.WOT jumps to 40 then levels back to 32. Fuel pump,FPR,or INJECTORS. please help thankyou

 

At idle, measure the fuel pressure WITHOUT the vacuum compensation line connected. Should read 43.5psi. Antyhing between 41-47psi meets GM specs. Reattach the vacuum line. Pressure shoudl drop about 8psi with a stock cam/vacuum. Then tape the gauge to the outside of the windshield, and watch the fuel pressure as you put the engine under heavy load on the road. Take it up to max RPM at WOT. Pressure should not drop below 40psi at any time.

The quick pressure bleed down after the pump primes will cause hard starting, but may not affect the way the engine runs. It's usually a problem with the check valve in the fuel pump, no affect on the way the engine runs. It could also be leaking injectors, or a leaking fuel pressure regulator. Both of those would affect the way the engine runs. Check the FPR vacuum line for wet fuel.

 

with vacuum unhooked it is like 41. wot seems to change anywhere from 30 to 40.it runs like a dog

 

Tried changing the filter lately?