I have a chevy cavalier it is not getting gas to the injector the fuel pump don't work unless its wired direct

Question

The fuel pump won't work unless it is wired direct first I thought it was the fuel pump relay but after doing all the test it says it's good but even when you hook the fuel pump up direct it still does not put anything out through the injector I have replaced the injector th ecm the fuel pump relay checked all fuses can someone please help me

Answer 1

check your oil pressure sending unit it is probable bad their is a relay that will cycle your pump on first start up but the oil sending unit is the switch that turns the pump on. good luck

Answer 2

Forgive me if this seems basic, I just don't know what else you've done besides your message indicates. I assume you have over 5 gallons of fuel in the tank -- If the gauge is anywhere below 1/4 tank then put a few gallons of fuel in. I've made this goof more than once, and all of us car guys will say the same thing.

Can your remove the injector from the fuel rail and watch fuel come out (with the pump running, and engine cranking)?

IF YES, fuel comes out:

Something may have gone wrong in the wiring between the ecm and the injector, such that the injector is not getting the signal to open up when cranking. That's the next thing I would suspect. I had an F350 Diesel do this to me, and it turned out rats had chewed the wiring in a few places. Took forever to find. Start by disconnecting the wiring harness at both ends, if you can, and checking for continuity all the way from the ecm connector to the injector. You might also be able to check this by monitoring the AC voltage at the injector while cranking, but I don't know what voltage to tell you to look for -- I assume 5 to 12 volts, a good manual will say. Finally, remember the injector may be stuck shut as well even if new.

IF NO FUEL COMES OUT:

Remove the fuel filter and see if you get fuel flow there (again, pump running). If so replace the fuel filter. If not, drop the tank and pull the fuel pump.

Best wishes.
-MB

Answer 3

the computer controls the fuel pump. the computer has to see one of two things before it will tell the fuel pump to operate. the first thing the computer is looking at is a simple timer. it turns the pump on for roughly 20 seconds. after the timer has expired, if the computer is receiving a tach signal, then it will also command the fuel pump on.
i have seen something like this before, and got stuck in a strange situation because of it. about 12 years ago, my neighbor bout a car. i don't remember the specifics for the vehicle but that is irrelevant.
the situation was this, if you tried to start the car, it would only crank, not fire. if you put a little gas into the intake, it would fire and run all day long. the owner assumed that the fuel pump was bad, and asked me to replace it. i did ,not the solution.
you may have to get the computer checked out, or possibly the distibuter...

Answer 4

i didnt see any good answers so heres whats wrong if the security light is flashing turn key on and leave it on for 15 min light should go out and repeat two more times and car should crank