5.7 chevy 1500 loses power
When i get on a hill and down shift the Engine loses power.
this truck had o2 sensor code with a vacccum leak that was
repaired. Fuel psi is 35. Could an o2senzor do this
Is it 35 at idle? While accelerating it should be closer to 45-50. If its 35 during acceleration its getting what's called fuel cut.
Does your truck seem hard to start or crank longer than normal? 1996-1999 vortec 5.7 require 60-66psi to start. Hook up fuel pressure gauge and just turn key on without starting it and check the pressure. Idle fuel pressure should be near 50psi, and under hard acceleration, should be back near 60psi. If you don't have enough pressure, 1st change the fuel filter, if that doesn't help, you need a fuel pump. Oh, and common sense here, make sure you don't have a leak somewhere.
having a problem with chevy votec 5.7. it runs fine till it gets to a moment where by it looses ecceloration and then it starts to run rough on less than 15 000RPM tryed the filters chacked all wires change the pedal sencor