I have a 93 F250 7.3 IDI non turbo. This morning I went to start the truck and it ran for a few seconds then quit. I then tried to crank but it would not fire. Fearing that I let the fuel in the tank get too low, I put 5 gallons in brining it up to just above half a tank. Still crank and no start, so i filled both fuel filters (previous owners installed a secondary), and cranked while holding the schrader valve open but couldn't get any fuel to come out. So I hooked my vacuum pump to it and was able to get fuel out of it but still couldnt get any fuel out of it while cranking. I then disconnected the fuel line coming off the lifter pump to the filter and cranked but no fuel came out. I pulled a vacuum on that line and was able to get fuel, but still none while cranking.

This is all leading me to believe that I have a lifter pump failure, but thats only my best guess from research. Does anyone else agree with that assumption or have any other diag to try?

Ive got a Dura-Lift pump on order that will be here tomorrow that I would like to put in and see if that fixes my problem.

I also have a mobile mechanic on the way that I called out of desperation because I really need this truck back up and running, but I would still like the yalls opinions as well.

 

I would agree that your lift pump crapped out. A duralift is a good fix. At some point make sure to remove the old lift pump and install a block off plate.

 

The mechanic confirmed my suspicions and told me I wasnt getting any fuel pressure at the filter. His hourly rate is pretty good and he's willing to install the dura lift pump for me so Im going to let him do it to save me time and frustration.

I do plan on taking out the old lifter and putting the blocking plate in during install of the new pump.

I just find it odd that there were no sign or symptoms prior to the pump going out. Hoping the dura lift saves additional time and frustration in the future.

 

If it's a mechanical fuel pump they usually leak when they fail. If it's not leaking externally it might be internal? I've not had that issue but read here of that possibility. Check your dip stick for rising level diesel smell.

 

^^^THIS^^^

I've had a mechanical lift pump fail on me more than once. They will pump diesel into the crankcase so make sure you check your oil level. I finally decided to install a Duralift electric pump. It works great.

 

If there's diesel in the oil should I do an oil change?

Also, I'm planning on taking the mechanical pump out completely. If the old pump is putting fuel in the oil, is taking out the old pump all I need to do to keep diesel from getting in the oil?

 

yes, and yes. you do not want to run oil that smells of diesel fuel, that mean it is thinned out enough to do harm to the engine over the long haul.
and removing the lift pump an installing a block off plate blocks the path from fuel getting into the oil.
when buying a e-pump, get a facet duralift 40222 pump
these guys have the best price i have found:
https://www.pegasusautoracing.com/ke...ywordButton=Go

 

I like the mechanical lift pump for it's simplicity. No wiring, safety shut off issues to worry about. I have been running the mechanical pumps for over 400K miles on my 6.9l. That said getting good replacement mechanical pumps made from chinesium is a crap shoot. That's why a lot of guys go for the electric option. I'm wondering about their quality as well. Maybe easier to change out once you're set up for the electric pump.

Just imagine the quality of new trucks full of Chinese parts. I'm sticking with old Blue as he's still mostly American made.

 

Facet duralift electric pumps are made in the USA. Black negative, red positive = simple too. No diaphragm to rupture and fill your base with diesel to worry about either.

"Since 1950, Motor Components, LLC has designed and manufactured Facet® and Purolator® electronic fuel pumps in our ISO 9001-2015 facility located in Elmira, NY."

Relay wiring is easy.



1.pin 85 - ground.
2.pin 86 - jumper off FSS line, on top of IP.
3.pin 87 - red/positive wire of pump. (negative wire of pump goes directly to ground.Combine into pin 85 if you want.)
4.pin 30 - wire from constant 12v source (right off + battery is ok) w/ an inline fuse holder (5 amp fuse).

Issue free for years. No more junk lift pumps. No more worry about ruptures filling base full of fuel. No more cranking of engine to prime fuel, from tank to pump. This is how these trucks should have left the factory.

Those fuel pumps are the best because they are made in the USA, solid state, and unlike many electric fuel pumps, they can pull 10 feet! You can mount them right up in the engine bay. I've been running them in my work trucks for a combined 2 decades.

Chevy big block 396/454 lift pump block off plate w/ ultra black RTV (no gasket required).

 

another good thing about the duralift is they are designed to lift fuel straight up 10 foot. thee pumps were designed for reefer trailers, as the refrigeration unit engine is usually up high on the trailer and the fuel tanks are low under the trailer. plus they last damn near forever.
best i got out of a mechanical pump was around 100,000 miles. the duralift on my 8 has been there for 400,000 miles, and around 30 years.

 

I am aware of the Duralift pump. When my mechanical goes belly up I'll go with it. I'm hoping that my mechanical lift pump will keep doing it's job though. If it works don't fix it is my motto.

Edit: If I could be assured of getting a decent mechanical lift pump I'd probably choose that route as it's an easy swap out. But alas how many mechanical fuel pump sad stories do we need to hear about. People are carrying spare ones now as some only last a few thousand miles.

 

that is what happens when the only parts available are cheap chinesium.

 

I would ask the mechanic to install the pump in a way that is easy to access. When I installed the Duralift pump one of the things I wanted was to make sure I could easily access everything if I needed a roadside repair. Almost 10 years/80k miles and no pump failure but i did have a relay fail which lead to the fuel filter light coming on as the IP was doing all the work. So it's worth carrying a spare relay or some bits of wiring to at least get the pump running again.

 

A couple relays in the glove box is good idea, but if not, you can always borrow the horn relay from the under hood fuse box.
If a guy wanted, he could go right ahead and wire in a road side emergency, backup plan also. You could tap into the wires of pin #87 and pin #30 with jumpers. Put the two jumpers on a toggle switch (anything rated for like 5 amps or higher is ok, I'd probably find something rated for 10 or 20, I think the pump only draws like 2-3, no need to spend big bucks for super high amp switch or anything). Then in the event of a relay failure, you can pop the hood, turn the switch on and have the pump run manually. If a guy wanted, he could even run these two wires into the cab and place the toggle right in there too. If fact, if you wanted, you could just run a toggle that you had to turn on/off manually, without using a relay at all.
All the relay is, is a switch you don't have to turn on/off manually, but you can have both or either or. That said, the little 30 or 40 amp bosh style relays are sold at every auto store and pretty cheap.

For those who want a relay w/ manual on/off, instead of using the FSS (key on) to run the pump, just feed your in cab toggle any 12v source (put a inline 5 amp fuse right there at the switch too, unless it comes directly off the battery, then place it at the battery. If you tie into say, the radio power, don't forget to check it's fuse in the event the pump stops too), and then the other line goes to your pin #86 to manually supply power to your relay trigger (hook everything else the same as posted in post #9). There's plenty of backup options..... But generally the relays last issue free for a decade or longer, so don't get too concerned about it. It's so rare, knowing I can rob a horn relay to get home or an auto store, is good enough for me (hasn't been needed yet unless I forgot about it. It would be uneventful enough, that's possible).