Hey fellows. I've not been around here much - I've still got my old 1990 project C4. I've not run it other than to start it everyonce in a while to keep the lubrication going in the last three years or so.

^ long story...

This last time I tried to start it - it wouldn't start. It'd probably been 4 or 5 months since the last time I started it --- too long I know. It turns over fine. If I use starter fluid it gurgles a bit like it's trying to catch, but won't fire up. I suspect it's not getting fuel. I do not hear the fuel pump running (but can't remember if I should). I took off the hose that represents what I believe to be the sending line and no fuel comes out when I turn the ignition key or crank the motor. I checked the connector with a multimeter outside the gas tank and at least to the connector itself I have 11 volts. (another problem I know - my battery is low) -- but I'm not getting any fuel at all out of the line I believe sends the fuel with the hose disconnected. So chances are it's a bad fuel pump right? I replaced the fuel pump a few years back with a used unit and the gas guage has never been right since. Would I be better of to buy a whole new assembly?


Is there a respected source for these assemblies these days?


This is my old sending unit which the fuel gauge complete failed that I'm using as a referene. The hose I disconnected is the one that my pointer finger is pointing at in the picture. It is the pipe on the side that is solo. The other side has two pipes. On the unit still in my C4 - the solo pipe should be spitting out fuel with the key in the ignition and the hose disconnected right?

 

No vette tech am I but I can tell you this. When you turn to the run position the pump should run for 2 seconds then run in the start position. Can you rent a fuel pressure tester? Do a Google search to find out witch wire is feeding the pump? You need good power and ground at the pump for any thing to happen. Are you getting spark? If it were me I would charge the battery and retest everything. Any codes?

 

When you first turn on the key the ECM will run the fuel pump (through the fuel pump relay) for 2 seconds to prime the fuel rail. It then shuts off so the pump won't run continuously if you turn on the ignition but don't start the car.

The place to look for voltage is at the wires that attach to the pump. Then you know the rest of the circuit is good.

Fuel should come out of the pipe that has the pulsator on it. The other large diameter pipe is for the return line and the small diameter pipe goes to the charcoal canister.

I bought an aftermarket sending unit after I accidentally burned mine up while testing the fuel pump. It's all stainless steel. Very nice. I think it's this one (didn't keep the receipt):

http://www.ecklerscorvette.com/corve...1985-1987.html

It looks like they vary by year, so check for one that is specific to your year.