I had my 95 Z stall on me in traffic yesterday.

Seemed like engine was sucking for air and fuel.

When I turn key to" on" , not start, i dont' hear anything, even with door open and me leaning down. But if fuel pump was dead, car wouldn't even start right?? I left key in "on" position and walked around back and knelt by fuel tank and no noise whatsoever!!

Funny thing, car starts and runs but it shut off yesterday at BP. Put in 5 Gallons of gas, started car, opened hood and stood there as it shut off again.

I checked relay by jumping two wires, pink and gray, with no relay harness on, and car starts. SO it's good right???

Checked schrader valve and fuel barely bubbling out?? Not 41-45 lbs as it should be.

But if pump is completely silent and dead, why does the car start and run???

Help!!!

 

pressure and flow are very different. You could easily have 45 pounds of pressure but a clogged filter would result in poor flow.

 

I just had it changed at Midas 1 week ago.

Maybe those bastards didn't change it!!! $50

Again, the fuel pump makes no noise whatsoever. I literally had my ear 6 inches from fuel tank!!!!

How the hell is the car running???

 

The fuel pump will only stay on for about 2 sec. when you turn the key on. So to be sure that you don't miss it have someone turn it on while you listen.

 

When you turn the key to the "on" position but don't start the engine, the fuel pump runs for about 2 seconds and the PCM shuts it down because there is no low res pulse coming from the Opti. By the time you turned the key on, got out of the car and listened at the tank, the pump would have shut down.

You need a real pressure gauge on the Schrader, and then measure the fuel pressure:

-Turn on key, don't start. Pressure should come up to 41 to 46psi, the pump shuts off, and the pressure should stay there with very little drop for the first few minutes. That will verify the pump is starting, and that the check valve in the pump and the fuel pressure regulator are doing their job, and that the injectors aren't leaking down.

-Take vacuum line off FPR (plug it) and start the car. Pressure should be 41 to 46psi. Put the vacuum line on.... pressure should drop proportional to engine vacuum, or 5 to 8psi.

-Now tape the gauge to the windshield, and take it to WOT at high RPM. Fuel should hold the 41-46psi value you got at idle/no vacuum.

Without actually measuring the pressure, we are all just guessing.