No Fuel Pressure

[Founding Father]

Hey there everyone - here is the situation:

My 2000 V6 Pontiac Firebird won't start most of the time, though when it does start it runs fine, though sometimes the engine cuts off all at once. I suspected a fuel issue, so I checked the pressure and it was 0. Furthermore, I don't hear the fuel pump kicking on when the key is turned to run. The fuse works, I checked the fuel pump relay and there was power going to it, so I moved on to checking the electrical connections near the fuel tank, and here is what I found:

There is a set of plugs that seem to connect wires inside the car to those external/underneath - there are three plugs which all connect to the same unit, 2 plugs with two wires, and a large plug which has wires A-G (I've attached a V8 picture to communicate the basic idea).

Using my voltmeter on the prongs coming out from the interior of the car, here is what I've found: On the 2 wire plug towards the middle of the car, there is a red wire with 12V, and a white wire with 0V. The 2 wire plug towards the side of the (which seems to be for two grounds) has a white wire has 0V, while the black wire has 4.7V. Lastly, on the A-G plug, A and D read 5V, while all the others are 0.

So, anyone have any ideas? It seems like it's either a grounding issue, or the pump itself is bad.

On a maybe related note, my aftermarket alarm system with added on power locks quit working 2 years ago, and I've recently noticed that my 12V plug ins and my OBDII scanner port don't have power. I don't know when this happened, or if it has any relation to the main problem above.

Thanks all!

-Justin

[j cAT]

place 12 volts to the fuel pump with a fused wire. also the ground wire connect to ground and see if the pump runs.

this will tell you if the pump is bad. if the pump does not run hit the fuel tank . if it then runs then the pump is N/G..

if the 12volt power sockets are dead check all fuses with a meter.

these fuses blowing are a common problem.

the large guage wires will be the pump feed. the other wires are the tank pressure/level etc...

I would replace the relay whenever the pump is defective and replace the filter. keep fuel above 1/4 at all times.

DO NOT USE AIRTEX PUMP.

[Tech II]

When it won't start......spray carb cleaner into the intake and see if it starts....if it does you know it's a fuel problem.......if you have pressure, it's an injector problem.....

If you have no pressure, then attach a test light to the fuel pump circuit in the harness to the tank.....turn key on, should light for two seconds.....crank vehicle and it should be on constantly....if it does, you need a pump......good luck.....that tank is a bitch to drop down....