QuestionI have a 1996 chevy 5.7 PU that will not start unless i pour some gas in the TBI
then it starts and idles but bogs when you try to drive it
the fuel PSI gage reads 54PSI max and drops to 14PSI when the engine is turned off
what is the correct pressure for this truck?
Answer54 is about right. Of course the pressure will drop OFF when you shut OFF the engine as your shutting OFF the electric fuel pump.
Fuel pump test:
1. Get yourself a helper.
2. remove the gas cap.
3. have one person listen in the gas tank at the gas cap opening.
4. have the other person turn the ignition switch to the ON position ONLY so as the dash lights come on. Do NOT attempt to start the engine.
5. As soon as the ignition key is turned to the ON position, The person at the gas tank should hear the fuel pump run for TWO SECONDS and then it should STOP.
6. Does it ?.
If you do NOT hear it run, in most cases the fault is the fuel pump.
The fuel pump circuits operates like this:
The computer sends a 2 second battery voltage signal to the fuel pump relay just as you turn ON the ignition switch. This primes the fuel system in order to start the engine quickly.
Once the engine starts, the computer BYPASSES the fuel pump relay and sends a constant continous battery voltage supply to the oil pressure switch of which is now CLOSED due to the engine running and the battery voltage passes thru the oil pressure switch and goes back to run the fuel pump constantly until you turn OFF the engine.
let me know.
autohelp
