I bought my car about 5 years ago and had a new gas tank and fuel pump installed 4 years ago. Around 2.5 to 3 years ago my injectors fried themselves so I replace them and at the same time the in line fuel filter. Two weeks ago when I got back from college, my car would barely start and stall as soon as I pressed the gas pedal. I pushed it up onto wheel ramps and rented a fuel pressure gauge from Autozone and the gauge is showing zero pressure when the key is in accessories and when I turn the starter. I pulled up the carpet in the back to look at the fuel pump (the floor hole was there when I bought the car don't kill me) and when the key is turned I audibly hear the pump running so I know that it's at least receiving power. I'm confused as to where I'm losing all of my pressure because the gauge doesn't even shift a little, so any help/ideas would be appreciated.

 

Do you have enough gas in it?

 

lol, yeah. It has just above half a tank full in it right now

 

There is a fuel pump cut off switch in the oil pressure sender. You could check/jumper that. But if its not building any pressure when it primes, its makes me think its the pump. I would try and jumper the oil press switch and see what happens to pressure. You could also just jumper the fuel pump and see what the pressure does. The fuel pump is ecm controlled. It could be a pump problem, a wiring problem or the ecm not running it for multiple reasons. Some simple diagnostics should get you an answer. At least it has an access panel if you need a new pump.

 

I did some more diagnostics today and this is what I've discovered--
I unscrewed the fuel lines right before the rails and injectors, and fuel does come out when I prime the engine (probably around 2-3 ounces of it).
I went back and used a multimeter on the fuel pump wires and was getting reading from 10.5V to 11.3V when I primed the engine.
I took out the pressure regulator on the fuel rail to see if that had failed but the diaphragm wasn't ripped and the spring still had a lot of force.
I know which of the 3 relays on the drivers side firewall is the one that controls the fuel pump, I tried switching it with any of the others; however, if I used any relay but the one that was on it originally, the fuel pump doesn't even run? (I'm not sure why this is, I could just be stupid).

At this point I can only think that either the gauge I'm using is faulty (but I still do have a fuel pressure issue as when I manually depress the Schrader valve pin gas trickles out instead of spraying put), or the pump is dumping most of the gas back into the gas tank or something. Any advice is appreciated!

 

Using a jumper wire is more about seeing if the pump will build proper pressure. If it does, then you know your pump works and something is not telling it to run. A pump can still move a little fuel but not enough pressure to run the car. Also, in the acc/on position it will always try and prime. What it is commanded to do once the engine is being started/rotating is a different deal. If the oil pressure switch is bad it will prime but not start/run long. There is always some residual pressure after the pump primes.

so the question is, is it the pump or something that controls the pump. By jumping the fuel pump relay, thats what you're testing. Also, your voltage sounds a little low, but that may be because its jot running.

 

Actually, the V-6 in some years used the oil pressure switch in series, but the V-8s all used that switch in parallel. That means the switch (for a V-8) does not interrupt the pump circuit. If a pump doesn't run while the engine is running, the problem is likely the relay, ECM, or ignition module wiring to the ECM.

 

Hi this my help

For my camaro was the fuel pump and fuel lines. Replaced the pump but same issue no pressure. Fuel lines on some locations had corrosion by the connector's (holders), the holes were very tinny, not visible with the eye. You can repair (rusted lines) or replace the fuel lines. I ended up replacing them. After that i had 40 PSI on crank or engine running.