99 7.3 no start where to start.

[yotekiller243]

I have a 99 super duty 7.3 last wed. I had the truck plugged in it was -21 degrees the truck started on the first crank. no problems. I waited about 5 min. and took off. I got about 2 miles from the house and she started lopping and finely stopped running all together. I tried several times that day to get it started it would go for about 30 seconds then quit again. I figured that the fuel jelled or had water in the line and froze up. the temp have been running around 40 degrees for the last couple of days. I have left the truck plugged in and had put the battery charger on it. today I finely got a day off to try and start it. with out any luck. I added 9-1-1 to it and followed the directions on the bottle. I also changed the fuel filter. it cranks strong but will not start. I am not getting fuel to the fuel chamber but I have been pouring the 9-1-1 diesel into the chamber. I disconnected the fuel pump and drained the fuel from the fuel chamber to the fuel pump reconnected it checked all the fuses. I don't think that i am getting power to the fuel pump and don't know where to start. this is my first diesel and I don't know much about them. except if I don't do the work the repair shops charge an arm and leg which I need. any and all help would be appreciated.

[NoRalPh]

OK, first, when you roll the key ON the pump should run for just a few seconds. Does it do that? (put your hand on it, sometimes feel is better than hear)

Does the WTS light come on? (shows the computer is running)

Could the fuel gauge be giving a bad reading? (are you close to empty?)

Does the tach needle move up slightly when cranking?

When you had the pump disconnected, did you try running it to check for fuel flow? (You'd have to "work" the key a few times)

[yotekiller243]

can not place hand on pump to check by myself and 30 miles from town. can't hear pump turn on.
wts light comes on.
fuel tank has 38 gal fuel.
tach needle moves
fuel pump did not pump fuel out tried the key several times.
can you disconnect wires from pump and run directly to battery to test?

[yotekiller243]

also all gps were replaced last summer. had 4 bad ones.

[NoRalPh]

You can run the pump separately powered. A Booster Pack makes a good tester. Before you bought a new one, certainly try to run it from the batteries once you remove it.

I assume you mean the CPS, the "tach needle movement" was the test for that

How about the infamous "Inertia Switch" in the passenger kick panel? It will kill the power to the pump.....

Basically the PCM controls the pump through a relay (behind the ashtray) and the Inertia SW, and a fuse.

[yotekiller243]

the tach needle did move so I assume that the cps is working. I did check and push the inertia switch on the kick panel earlier today thinking that may help. the relay behind the ashtray didn't even know it was there I will have to check that in the am. any other things to check?
and thanks a bunch for the help really appreciate it.

[yotekiller243]

more help needed. I disconnected the fuel line from the front of the pump going to the fuel filter reservoir and disconnected the leads going to the pump. I hooked the pump to the battery and hear it turning however I am not getting fuel from the tank. I ran it for about 45 seconds. should i have run it longer? is there a filter inside the tank and can that be plugged? can the pump be vapor locked if or is the pump bad? I picked up a volt meter today I still don't know if there is power going to the pump. What should the meter read when I turn the key on to the pump I just bought the meter today.

[STANGMAN893]

When my factory pump failed it made noise hummed and you could feel it running but no fuel.I wasn'tsure of the tank so I got a 5 gal fuel can and slipped a hose over the tank side of the pump and dropped it in the container.No fuel so I got a new pump and all is good now.Try that and see and then drop the diesel in the tank and your good to go.

[NoRalPh]

Originally Posted by yotekiller243

more help needed. I disconnected the fuel line from the front of the pump going to the fuel filter reservoir and disconnected the leads going to the pump. I hooked the pump to the battery and hear it turning however I am not getting fuel from the tank. I ran it for about 45 seconds. should i have run it longer? is there a filter inside the tank and can that be plugged? can the pump be vapor locked if or is the pump bad? I picked up a volt meter today I still don't know if there is power going to the pump. What should the meter read when I turn the key on to the pump I just bought the meter today.

Fuel should be coming out of the pump sooner than that... So, it sounds like either the pump isn't "pumping" because it's bad OR it's either sucking air in the tank or the supply line because the level in the tank is too low, the screens are plugged, or the line is broken somewhere.

Sounds like it might be time to pull the pump for further testing. You could run it with the suction side in fuel to see how it pumps maybe,,,, If you had a vacuum source you could also see if you can draw from the supply line.

Is the tank up over 1/2 full? Could the gauge be bad and giving a false reading?

You should find battery voltage at the pump when you first roll-on the key (at least for a few seconds) The PCM provides a path to ground to energize the relays coil and close the contacts of the relay to supply power to that pump.

The other thing to consider is,,, if it's the original pump and 10yrs old, you're doing all this outside in the cold, maybe just throw-in a new one and see if it pumps (what are you really losing even if it Isn't the pump? How much longer would it have gone... )

[yotekiller243]

well I found the problem the fuel line between the tank and the pump was froze. I disconnected the pump from the truck and put a lead from the intake to a gas can the pump worked fine. I hooked it back into the truck and it wouldn't work. I disconnected it a second time and tried it again again it worked. again hooked it up again it didn't work. checked the power and had power, disconnected it a third time. then opened the gas cap put a rag around an air compressor hose and put air into the tank chunks of ice came out of the fuel line. hooked the pump back up primed the fuel reservoir turned the key and away it went. I want to thank everyone that helped figure this out. again thanks for the help
yk