1985 C4 Fuel pump
Thread Starter
2nd Gear
Joined: Dec 2018
Posts: 2
Likes: 0
1985 C4 Fuel pump
Hello, I recently went to start my C4 when I noticed I didn't hear the fuel pump. I then went to check my fuse and it was fine. Next I just replaced the pump because it was and old one anyways. But no luck, I then changed the fuel pump relay and still not luck. The fuel pump is still making a sound not working. Any thoughts?
Heel & Toe
Joined: Dec 2018
Posts: 16
Likes: 1
From: Hendersonville TN
could be a bad fuel pressure regulator or a clogged fuel filter. Could also be that part that pressure fits to the fuel pump, I think they call it a pulsaiter. Did it come with a small section of hose and 2 clamps when you got the new fuel pump?
Last edited by Vettenut1985; Dec 26, 2018 at 07:26 PM.
Team Owner
Joined: Jul 2004
Posts: 28,472
Likes: 3,290
From: Hartford WI
Have you checked to see that the pump is getting power? It should turn on for a second or two when you turn the key for the first time. So if you turn on, it primes but it should not keep priming if you turn they key on, off, on, etc. If it gets power, we look at the pump. If not, we look at something else in the circuit.
Pro
Joined: Mar 2000
Posts: 690
Likes: 7
From: Bradenton, FL
Cruise-In II Veteran
The fuel pump can be jumped to run continuously at the aldl connector. Just supply 12 volts to pin g, use a heavy guage wire (#12). If you hear it running, then check fuel pressure. To check for a bad regulator clamp the return hose and see if the pressure comes up to spec...
Safety Car
Joined: Aug 2009
Posts: 3,751
Likes: 276
From: Melbourne, Victoria, Australia
As Aklim mentioned, first check where the problem is.
Check power at the wiring connector to fuel pump assembly, 12 volts for a couple of seconds when ignition is turned on.
Then check the fuel pump relay on the firewall, there is a fuseable link that supplies battery power at all times is that open?.
The fuse box fuse supplies power to the coil circuit in the relay only, can you hear the relay click when turning ignition off / on?
Good luck
Check power at the wiring connector to fuel pump assembly, 12 volts for a couple of seconds when ignition is turned on.
Then check the fuel pump relay on the firewall, there is a fuseable link that supplies battery power at all times is that open?.
The fuse box fuse supplies power to the coil circuit in the relay only, can you hear the relay click when turning ignition off / on?
Good luck
