Fuel pump questions maybe?
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Fuel pump questions maybe?
I just want to say, I have no experience with working with diesels, I’ve only worked on gas-powered engines, but then again I learn as I go.
Okay, so here’s the problem. I’m in the process of looking for a good diesel work truck, and I found one that was a 92 F350, with the 7.3l idi, manual tranny. The guy is selling it because of a fuel pump problem and doesn’t have the time to work on it. Problem is, he was messing with the fuel pump, and from what I can gather, was trying to turn the fuel pump “up”, and ended up making it not start. Now, from my understanding, is that the fuel pump is mechanical, and operates off of the camshaft lobe, which is done through a long arm that builds fuel pressure so it can be distributed. Could he of turned the fuel pump up too much to where it flooded the engine? Or something worse? Is it fixable, or even worth fixing? Is it possible that he only cranked it once and because he drained the fuel out, it didn't start?
I should also note I haven’t bought it yet, but rather came here to see my options to see if it’s worth fixing.
Okay, so here’s the problem. I’m in the process of looking for a good diesel work truck, and I found one that was a 92 F350, with the 7.3l idi, manual tranny. The guy is selling it because of a fuel pump problem and doesn’t have the time to work on it. Problem is, he was messing with the fuel pump, and from what I can gather, was trying to turn the fuel pump “up”, and ended up making it not start. Now, from my understanding, is that the fuel pump is mechanical, and operates off of the camshaft lobe, which is done through a long arm that builds fuel pressure so it can be distributed. Could he of turned the fuel pump up too much to where it flooded the engine? Or something worse? Is it fixable, or even worth fixing? Is it possible that he only cranked it once and because he drained the fuel out, it didn't start?
I should also note I haven’t bought it yet, but rather came here to see my options to see if it’s worth fixing.
Logistics Pro
Joined: Jun 2017
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From: Edmond, OK
Be wary. "Turning up" the fuel pump references a fuel delivery screw on the side of the injection pump. This is what you can adjust if you want to "roll coal." The problem is that if you start delivering more fuel to the engine your temps will rise and you could cause the engine to self destruct. Does the truck have a pyrometer?
The mechanical lift pump is on the front of the engine near the bottom. As you said, a lever arm rides on an eccentric that causes the fuel pump to actuate.
The mechanical lift pump is on the front of the engine near the bottom. As you said, a lever arm rides on an eccentric that causes the fuel pump to actuate.
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Be wary. "Turning up" the fuel pump references a fuel delivery screw on the side of the injection pump. This is what you can adjust if you want to "roll coal." The problem is that if you start delivering more fuel to the engine your temps will rise and you could cause the engine to self destruct. Does the truck have a pyrometer?
The mechanical lift pump is on the front of the engine near the bottom. As you said, a lever arm rides on an eccentric that causes the fuel pump to actuate.
The mechanical lift pump is on the front of the engine near the bottom. As you said, a lever arm rides on an eccentric that causes the fuel pump to actuate.
Logistics Pro
Joined: Jun 2017
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From: Edmond, OK
RUN! 
If the fuel delivery screw is broken you would have to disassemble the injection pump to replace it and return it to 0. Unfortunately, you need precision measuring tools to set the delivery screw to the OE position. When the IP is "turned up" you rotate it a flat or two (60*-120*). A pyrometer lets you know if your exhaust temps get too high.
If he hadn't messed with the IP it might be a worthwhile project. When I first bought my Bullnose I pulled the ring on the OE water separator and caused some major air intrusion. It took me a week or two to get it running again.
If the fuel delivery screw is broken you would have to disassemble the injection pump to replace it and return it to 0. Unfortunately, you need precision measuring tools to set the delivery screw to the OE position. When the IP is "turned up" you rotate it a flat or two (60*-120*). A pyrometer lets you know if your exhaust temps get too high.
If he hadn't messed with the IP it might be a worthwhile project. When I first bought my Bullnose I pulled the ring on the OE water separator and caused some major air intrusion. It took me a week or two to get it running again.
Logistics Pro
Joined: Sep 2007
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From: Western Mass
I will counter that depending on what he is asking, and how cheaply you can find a working injection pump, it may be worth it. As Olds64 said you likely will not be able to use the existing pump as is.
If the truck is in good shape it might be worth your while. Especially if you are not afraid to do some work yourself, and have a decent junkyard nearby where you might be able to find a pump for cheap. However, if you don't have access to timing tools, and haven't worked with a diesel before, this may be out of your realm.
Where are you located? and what is the guy asking?
If the truck is in good shape it might be worth your while. Especially if you are not afraid to do some work yourself, and have a decent junkyard nearby where you might be able to find a pump for cheap. However, if you don't have access to timing tools, and haven't worked with a diesel before, this may be out of your realm.
Where are you located? and what is the guy asking?
Logistics Pro
Joined: Nov 2013
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From: Mojave, Ca
It also depends on which 'screw' he broke. There is a cover plate on the side of the injection pump that allows access to the fuel screw. That cover plate is held on with 2 screws. If he broke one if those, fuel will pour out of the IP and itll never start.
In my opinion, you cant break the fuel screw. Its a hex-drive and its in a very awkward spot. You'll round off your allen wrench or the fuel screw before you break the fuel screw.
In my opinion, you cant break the fuel screw. Its a hex-drive and its in a very awkward spot. You'll round off your allen wrench or the fuel screw before you break the fuel screw.
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Broke fuel pump tapper
I accidentally dropped a tappet on my first fuel pump replace. 1995 powerstroke. This was long before internet help. Did not know to hand crank motor till pump popped up. Any way it went down and was no way to drill. Wile trying to fish it out it just fell to oil pan. I put the old tappet in new pump and it stayed there until i change pan 200k miles later. Good luck
i ain't rite
Joined: Mar 2005
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From: Marlboro Mental Hospital.
I accidentally dropped a tappet on my first fuel pump replace. 1995 powerstroke. This was long before internet help. Did not know to hand crank motor till pump popped up. Any way it went down and was no way to drill. Wile trying to fish it out it just fell to oil pan. I put the old tappet in new pump and it stayed there until i change pan 200k miles later. Good luck
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