1982 Corvette Won't Start No Drive Signal to Fuel Pump Relay

[1930u]

Hi all- I have a no start problem with my 82 collector car. Here's some general info. about the car. It's completely stock with 64,000 miles. MFD 6/82 car #6,346. The car hasn't been driven in about 2-years. The fuel pump was replaced at some point in the past, not sure when, as I'm the second owner. Fuel level is just over 3/4 of a tank.

Facts and what I've done so far...

• Re-installed the battery and the voltage is 12.7
• Engine cranks over well but won't start
• If I fog the injectors with starting fluid it will start and then stall
• Engine cranking and with just the key on cycle, checked for voltage at fuel pump connector under the fuel filler door and have none
• Checked fuel pump fuse, crank fuse and the fuses for injectors and all are good
• Checked the power fuse and wiring for ECM in the battery compartment and all is good
• Checked for 12V at oil sender switch and all is good
• Also placed a jumper across the oil sender switch female connectors and the fuel pump will start and run but the car will not start and no fuel spray from the injectors
• I also applied 12 volts to the fuel pump pin on the diagnostic connector and the fuel pump will run
• Next I located and removed the fuel pump relay and bench tested it and it works perfectly
• I reconnected the fuel pump relay and checked for signals to the relay
• The relay has 5-wires; tan & white, black and white, dark green and white, red and orange
• Terminal A to fuel pump tan/white wire has 12V when I crank engine after the oil pressure builds
• Terminal B ground black/white wire, I connected an extra ground here and it changed nothing
• Terminal C fuel pump drive signal, dark green and white wire no voltage here not even the momentary two second key on voltage
• Terminal D diagnostic red wire, all good here if I apply 12V the pump will run
• Terminal E battery feed orange wire, 12 V here all the time just like to the oil sender switch.

I believe no signal to the relay terminal C driver terminal is the problem. The dark green and white wire. I figured this out with a PDF basic wiring diagram from the web but now I'm stumped as to where to go next.

The schematic shows the terminal C dark green/white wire connector 465 going to A1, 12 Volt Relay Drive and I don't see this any where in the schematic. Do I need another diagram of the ECM that shows where this wire goes? Physically it looks like this wire heads back up to the front of the car via the console hump area. Can I apply 12 V to this wire while the relay is connected to see if the car will start? I'm worried about shorting out the ECM.

I greatly appreciate any and all info on this and thanks for the help in advance!!!!

1930u

 

[bill81vette]

you stated its been 2 years since its been started,
you might want to get the old gas out of the tank and try some new gas.

 

[1930u]

Forgot to mention...drained the tank while in storage...all new fuel now....thanks though.

 

[bill81vette]

You may have to change out the fuel pump in the tank.....

Sent from my SM-T827V using Tapatalk

 

[Tom Bryant]

I'm suspicious of the fuel pump relay even though it bench tested ok. They run about $35.00 and given the age of the car it would be good to have one on hand even if it doesn't solve the problem. Also injectors gum up if let sit for a long period of time so you may have a problem there too. Logic dictates that you first have to get fuel to the injectors before a gummy injector can be the problem but it's something to think about. Was there any sign of any rodents in or around the car when in storage? They love wiring insulation.

Did you check the fuel pump fuse for continuity or just a visual check? I've had fuses that were blown but appeared to be good.

When you jumped the fuel pump with a 12v source did you try to start the engine when the pump was running?
Try cracking a fuel line at the engine and run the fuel pump, ignition off, to see if you have fuel pressure from the pump. Wrap a rag around the line to prevent fuel from spraying everywhere.

I'd try changing the fuse first and the relay second just to see what happens.

Tom

 

[Antz81]

When you jumped the fuel pump with a 12v source did you try to start the engine when the pump was running?
Try cracking a fuel line at the engine and run the fuel pump, ignition off, to see if you have fuel pressure from the pump. Wrap a rag around the line to prevent fuel from spraying everywhere.

Since he can get the pump to run and his tests indicate that either the relay or the oil pressure switch should be starting it this is what i would check. Just because its running doesn't mean its pumping.

 

[Larryg199]

1930u... hello. I just jumped on here because I was having a no-start condition with my 82 Collectors Edition also. I immediately saw your post and am now following it. Did you get the situation resolved ? Your situation sounds almost exactly like mine, only mine has been sitting for only about a year. I removed the fuel line to the throttle body and have no fuel there. I have power to fuel pump relay terminal A and C with the key on, but no power to B & E even when cranking. My situation same as yours in that when I use starting fluid it fires but then of course quits once the starting fluid burns off. Where did you locate the fuel pump fuse at ? All my fusees on the fuse panel test good.

Larry