NO FUEL PUMP OPERATION - NO CONSTANT POWER TO FUEL PUMP. HELP... 1991 Camaro v6. Sitting but run every few months... Was low on fuel, started up to go TO gas station, and seemed to run out of gas... Put 4 gallons of premium in tank... Still would not start. Began testing...

The FUEL PUMP DOES NOT RUN - SO, I replaced the FUEL PUMP RELAY. Still nothing.. I connected 12volts TO the RED PRIMING WIRE, still nothing... BUT, I did not test for voltage under the car since I was alone and possible fire hazard... IF I turn the key on and check for voltage at the wires within the cabin behind the back seat, I get 12 volts for about 2 seconds and then the voltage drops again... to .3 - or what I consider a phantom voltage, but certainly not enough to fire the pump... I NEVER HEAR THE PUMP RUN, at least for the 2 seconds... I cleaned the RESISTOR / CHIP in the key, thinking VATS issue, but no luck...

The problem is I get NO FUEL to the engine... It will run if you put a little gas within the air filter... SO, I KNOW I have ignition and of course the car turns over perfectly... Any ideas>?

 

Either the fuel pump is bad or the bulk-head connector on the sending unit is bad. The +12 volts for 2 seconds at key-on, engine-off is correct. This is the ECM's prime for the fuel rail pressure.

Not a VATs issue...

RBob.

 

I would agree, EXCEPT... I HAVE PRIME VOLTAGE on the grey wire. I have verified the ground... There is no CONSTANT voltage to run the pump... It appears that I have no CONSTANT VOLTAGE to run the pump and that is what I suspect to be the issue. According to 3RD GEN the VSAT can INTERRUPT the CRANK and the FUEL CIRCUIT. It cranks perfectly. I have known spark. I just have NO fuel pump operation... It just QUIT after moving the car 20 feet...

I hate to drop the tank, and REAR END AND SHOCKS to find it was a simple issue, like wiring or computer...

 

Been doing to searching.. On FIREBIRD NATION, I was able to locate some info...

FIRST, I can not find a FUSE for the FUEL PUMP. With the help of FIREBIRD NATION and YOUTUBE, I discovered there is a 10 AMP FUSE ASSEMBLY, EXTERNAL, on the INNER FENDER WELL.. FOR THE FUEL PUMP... WHY? WHAT WAS GM THINKING? I HOPE this will resolve my issue, as I HAVE NO POWER to the fuel pump when in the run position. Also, no power when I even apply 12Volt power to the PRIME CIRCUIT... I HOPE THIS IS MY FIX~! I want to take the Camaro for a good run! Plus, I want it SAFE for my daughter to operate with no issues... Please feel free to continue to give advice in case this is not the fix... But I think it is a GREAT LEAD!

 

If that's not your issue its probably your ECM. I had the same issue, ended up being a blown transistor on the ECM that controls power to the fuel pump.

 

I did check the fuse at 5 am before going to work and it is
fine. There are 3 wires going through the rear bulkhead... GRAY...
BLACK AND PURPLE. PURPLE APPEARS TO FUEL LEVEL AS I GET 2.84 VOLTS.
GROUND IS GROUND AND THE GREY SHOULD BE PUMP POWER... CORRECT?
so... If I apply dv voltage to the grey wire pump should start?
Correct? Also the pump relay DOES CLICK. I DO GET PRIME VOLTAGE FOR 2
SECONDS BUT PUMP WILL NOT RUN... Just want to be clear as possible..
So any way to test the ecm???