Fuel Pump Failure or Electrical Problem??
You should get a healthy squirt of gas when you press the valve in. Can you hear the pump prime when you turn the key on?
So you hear the relay click by the pedal, but no prime. So the fuse is good then. Underneath the rear of your car by the gas tank there should be a grey wire that gets 12v when primed/running. If you get 12v there then your pump is no good.
Also pay attention to the black ground wire at the fuel pump electrical connector. A motor won't run without a ground connection.
If both the gray and black wires check out, then the pump is no good.
If both the gray and black wires check out, then the pump is no good.
click the how to then click number 33 here 4th Gen LT1 F-Body Tech Aids
lots of good info, now i see you have a 3.8, allot of the info is good for 93-97 4th gens
lots of good info, now i see you have a 3.8, allot of the info is good for 93-97 4th gens
Last edited by craby; Nov 21, 2013 at 08:23 AM.
UPDATE (Dec 14, 2013:
1.) Fuse and fuel pump relay are good
2.) Pump does turn on (I can hear it prime)
Fuel Pressure Test:
With the tester connected to the schrader valve on the fuel rail, I turned the key to the ON position in which there was NO PRESSURE present. The gauge didn’t budge.
Checking the Grey wire on the Connector:
Before testing, I cut a little of the insulator to probe the grey wire with a volt meter. With the connector still attached, I probed the grey wire with the red lead and placed the ground (black) lead on the chassis. Then had a buddy turn the ignition to the ON position. I did NOT get any voltage.
Car cranks but still doesn’t start up.
Am I missing something here? Did I test something wrong? Let me know guys any help is appreciated.
1.) Fuse and fuel pump relay are good
2.) Pump does turn on (I can hear it prime)
Fuel Pressure Test:
With the tester connected to the schrader valve on the fuel rail, I turned the key to the ON position in which there was NO PRESSURE present. The gauge didn’t budge.
Checking the Grey wire on the Connector:
Before testing, I cut a little of the insulator to probe the grey wire with a volt meter. With the connector still attached, I probed the grey wire with the red lead and placed the ground (black) lead on the chassis. Then had a buddy turn the ignition to the ON position. I did NOT get any voltage.
Car cranks but still doesn’t start up.
Am I missing something here? Did I test something wrong? Let me know guys any help is appreciated.
Last edited by 96WhiteStallion; Dec 14, 2013 at 04:27 PM.
Unplug the harness from the body socket and put the volt meter on the 1st and 3rd pin (the grey and black wire pins). You could've had a bad ground on the chassis due to rust or whatever. Also, if you hear it prime but the gauge didn't bulge it could be a weak pump or the gauge is broke. Try it without a gauge, just let it prime and see if fuel squirts out when you poke the valve. Let us know the result so we can see if we have to dig deeper for the issue.
If you hear the fuel pump prime (runs for 2 seconds after the ignition is switched on , then stops), there is no need to check the wiring any further. You may have been using the meter wrong when you got zero volts, or the wiring has been bypassed.
Do as directed above and watch for fuel coming out the Schrader valve (held open) on the engine fuel rail when you do the prime. If fuel comes out, but there is no pressure build up with the valve closed, either the pump is bad or the regulator is stuck open. Pull the vacuum line off the regulator and see if fuel comes out while priming. If it does, replace the regulator. Even if it doesn't come out, the regulator can still be bad. If no fuel comes out, the pump is bad or the tank is empty.
Do as directed above and watch for fuel coming out the Schrader valve (held open) on the engine fuel rail when you do the prime. If fuel comes out, but there is no pressure build up with the valve closed, either the pump is bad or the regulator is stuck open. Pull the vacuum line off the regulator and see if fuel comes out while priming. If it does, replace the regulator. Even if it doesn't come out, the regulator can still be bad. If no fuel comes out, the pump is bad or the tank is empty.
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Gary's is right on, if you hear the pump prime and you are show no voltage you are doing something wrong. How could it run without voltage?
Never strip a wire of its insulation you are asking for trouble down the road. Disconnect the connector. If you really want to test it for voltage while it is connected use a test light with a sharp tip and poke a tiny hole in it. The insulator will just close up around the hole as long as it is small enough.
FYI fuel pump failure is very common in all 4th gens. I would guess 8 out of 10 no starts on the 3800 with no other symptoms end up being a bad fuel pump.
Never strip a wire of its insulation you are asking for trouble down the road. Disconnect the connector. If you really want to test it for voltage while it is connected use a test light with a sharp tip and poke a tiny hole in it. The insulator will just close up around the hole as long as it is small enough.
FYI fuel pump failure is very common in all 4th gens. I would guess 8 out of 10 no starts on the 3800 with no other symptoms end up being a bad fuel pump.


