1994 F350 IDI - mechanical fuel pump

[Scottintexas]

I know, it's what I signed up for,

The truck starts easily every time with the new starter, glow plugs, batteries,
it drives great after the new front suspension and brakes,
I had fixed all the leaks and not a spot underneath until....

I took a 10 mile drive last week and thought I smelt diesel, figured I had another leaking return line on an injector, when I got home I checked, the top side has never been drier, even the valley pan is starting to flake and previous dirt turn to dust,

after further inspection the mechanical fuel pump was soaked, I turned it on and it would spurt 2-3 drops out, on the engine side of the metal circular part of the pump towards the engine every second, I couldn't tell where it was coming from, the drops where flying 2-3 inches upwards and with the engine running wasn't going to look to closely!

It didn't look like any fuel was coming from the hose connections.

I checked the oil and it was still at the low mark with no fuel smell.

So after reading, I'm assuming/hoping the fuel is coming out of the weep hole that I can see indicating the pump is bad.

So my mechanical friends, @zipper @Babin Farms

This pump is probably 7-10 years old with 20k miles on it, I don't know the brand, a friend changed it when I had hot starting issues (turned out to be the solenoid on the IP)

Many have converted to an electrical pump on these. Do you think it's worth it ? I need easy but I want reliability and frankly getting that arm under the cam lobe sounds intimidating to me (but so does wiring the electric pump!)

 

[Scottintexas]

yellow is the fuel drops, green is the direction it was going,

with the truck running I couldn't see where the drops were coming from or how much the fan was causing the direction,

 

[Babin Farms]

I would probably just install another mechanical pump. I like simple and for $20-30 you can't go wrong.

If you do any maintenance on your boat then installing is going to be easy enough for you, don't sweat it. Just pay attention to the way the old one comes out and install the same (tension on pump arm and angle to remove)

1994 FORD F-350 7.3L V8 DIESEL Turbocharged Fuel Pump | RockAuto

 

[zipper]

Agree with above, as long as it was working before you noticed a leak. Assuming the lobe it rides on is still good. 10 years is pretty good if it was an after market part.

I can't believe how little rust I see in there. Our 90 f450 was very rusty.

 

[Scottintexas]

7.3 IDI Fuel Pump Replacement & Test Information

Step-by-step guide to testing and replacing a fuel lift pump on a 6.9 or 7.3 IDI diesel engine. Includes factory fuel pressure spec, testing equipment overview, and complete procedures for fuel pump replacement.

www.dieselhub.com

So i'm confused,
I have the old pump off, the instructions from diesel hub say to make sure the cam lobe is up so that the arm goes underneath, they have a picture included

I'm not sure if my lobe is up or down, YouTube and two pictures attached, supposed catastrophe failure if i install wrong

@Neutron @Babin Farms @zipper @djetok

 

[zipper]

Hard to see/follow in the video, but it looks like the lobe is down. The other guys should chime in soon.

 

[Neutron]

Looks down to me as well. You can install it that way, it just makes it harder because as you push the pump upwards to line up the bolts. So to make it easier bump the engine with the starter to get the lobe facing away from the direction

 

[ChrisM]

The Delphi offered on Rock Auto may be the OE supplier, here is your Ford part number, remember Ford branded parts are 2 year unlimited mileage. I always buy OE From ford for my 7.3.



The Tasca price..

 

[Scottintexas]

So i bumped it over, picture is terrible, i put the new pump up as a test fit and had absolutely no tension on it, i even tried tilting it when inserted and nothing, just loose and bolt right on, could i have been that lucky?

I think I'm going to buy an inspection camera tomorrow to get a better look at it

Another oddity, i put the pump on my bench to work the arm and it only travels about 1/4 to 1/2"

 

[Babin Farms]

Sounds like your a lucky guy. That’s normal travel because the lobe is only going to move it that much.

 

[Scottintexas]

Bubba said "cam lobe, nah just angle it down and slap it on", again it slid right in, no resistance, bolted it on, i did have to undo the hard line at the filter to attach it at the pump first but no leaks and no catastrophic failures

 

[Scottintexas]

Thanks for all the advice


.

 

[Neutron]

Glad it all worked out

 

[zipper]

Glad it went back together. I asume she is running? To be honest I never paid attention to the cam position when I have changed mechanical fuel pumps. Caviat...never changed pump on a 460 turbo diesel. The rocker arm and its movement is designed to follow the cam profile, as long as it is the right pump. The pump will bolt in and the resistance is dependant on the spring in the pump.