No getting fuel delivery to rail

We need to rule out a physical blockage in the line. so I would start at the pumps and unhook the supply line and energize the pump and run a rubber line off the supply line into a bucket and make sure the pump is pumping when it is turned out. We can't rule out a faulty pump until we confirm that when you hear it running that it is actually sending fuel.

Once you do this, just hook the line back up and move up the line and disconnect it again, and do the same thing. Basically just work your way up to the rail until you are not getting fuel. Then we know where the issue is.

Let me know what questions you have and we can go from there. Thanks

Thank you for replying. Would a blockage cause the fuel pump not to come on? As i said earlier, if i bypass the relay, both pumps run. There is a small amount of fuel in the rail but obviously not enough pressure to register on the gauge. I will try disconnecting the outgoing side of the pump to check volume.

Maybe I misunderstood. I thought the pumps came on normally. I didn't read that closely enough.

It would not cause that but with that info, you may have two issues. If you can jump the relay and still get no fuel when the pumps come on, then I suspect you have a blockage or a failed pump. Due to the pump being new, you would think there is a blockage which is why we need to confirm it is coming out of the pump. Once we solve that issue and you are getting fuel to the rail and proper pressure, even with jumping the relay then we can tackle why you are not getting power.

Okay. So i disconnected the output side of the primary pump and energized them by bypassing the fuel pump relay. They are definitely working. Hooked it back up and reinstalled the pressure gauge to the shrader valve energized the pumps again and read 38# pressure. Disconnected my jumper and watched for drop in pressure and it was marginal, maybe 2# over 5 minutes. I have replaced the relay 3 times with the same issue each time. The EEC relay is closing because you can feel it clicking when the key is turned on. Still wont start even with jumper over fuel pump relay. Any ideas?

Okay, so I disconnected the output side of the primary pump and energized them by bypassing the fuel pump relay. They are definitely working. Hooked it back up and reinstalled the pressure gauge to the schrader valve energized the pumps again and read 38# pressure. Disconnected my jumper and watched for drop in pressure and it was marginal, maybe 2# over 5 minutes. I have replaced the relay 3 times with the same issue each time. The EEC relay is closing because you can feel it clicking when the key is turned on. Still wont start even with jumper over fuel pump relay. Any ideas?

Hi,

When you provided power direct to the pump, did you check to see if there was power in the harness? If you are jumping at the relay and the pump doesn't run, then you have an open circuit between the two locations.

Let me know if you checked to see if there is power to the pump. Also, let me know if you checked to see if the inertia switch needs reset.

On F-series, the Inertia Switch is located at the far Left part of the toe-board, near the parking brake assembly.

Let me know.
Joe

Hi Joe. Thanks for the response. I have been using a jumper wire at the back of the fuel pump relay to power the pumps. The inertia switch isn't tripped and to cross check it i ran a jumper across it, in essence bypassing it. I have power to the relay with key on, but no power out of the relay. If i jump the relay i get power to the pumps, 38# of pressure at the test port, but still no start. I know i have fire from the distributor because it will try to start on starting fluid. I'm pretty stumped.

It actually wound up being a broken ground wire for the pump. Located right next to the battery of all places! Couldn't have got it without all your guys' help!
Thanks a million!

That is great information. Thanks for that update and I am sure that info will help others. Please come back to 2CarPros the next time you need some help. Thanks