Replacing the Fuel Cutoff Solenoid?

[Pele]

is your fuel pump working?

Mechanical pump is working. Fuel gets to the filter.
Have no clue how to diagnose the injection pump.

The filter was nasty.... Like how? Did it have a thick black goo in it? Black goo= algae, which is a real problem to get rid of.

No goo... Just brown dirt; solid particles. Enough to clog it probably.
Most likely knocked into the tank from when I had the pickup assembly off a few months ago.

When I replaced the glow plugs in November, I also resealed the pickup where it attaches to the tank. The truck would leak fuel when you filled it.

 

[Pele]

Any more help?

I'm getting harassed by the county to move my truck or they'll impound it.
Do I really need to spend on a new injection pump or is there anything I can do quickly to get this thing running?

If I need a new injection pump, can I do the swap in a parking lot with basic hand tools? I don't know how to time a Diesel. I'm fairly certain that a timing light for a gasoline engine won't work.

 

[Pele]

I've been over the fuel system servicing article a couple times and it doesn't have anything on Exercising the Metering Valves.

 

[Diesel JD]

Okay so you either have a bad governor cover or something badly wrong with the pump internally like a sheared pump shaft. If it was air you'd have been up and running by now. Here's how you might can get by cheap on this. Go to the boneyard and pull the governor cover off of any 5.7, 6.2, 6.9 or 7.3( I believe they will all work) if you find a 6.9 or 7.3 grab the whole pump if its cheap. It's also good practice. Yes this can easily be done in a parking lot. The worst part is getting the mounting bolts that mount the injection pump to the timing gear cover. You need the following tools 1) a 9/16 box end wrench, preferably ground down and bent as per Biofarmer93's article, but if you're patient most box end wrenches will work. I also remove the fast idle solenoid and throttle springs to gain easier access to the bottom nut on the timing gear cover. Do not remove the timing gear cover. You need to remove the oil fill spout. Behind it you'll find 3 5/16 or 8mm(interchangeable) 12 point bolts. I've pulled them with a variety of 5/16 and 8mm box wrenches and sockets, all work, but they must be 12 pt. You'll also need a 5/16 box wrench preferably with a 1" box wrench to use as a backup wrench. Write back and let us know how it goes.

 

[Pele]

Well, if it's the pump, I might as well just grab a new pump offa eBay.

 

[Diesel JD]

We don't know for sure it's the pump and not the solenoid. The solenoid is cheap in a boneyard and maybe even from some other OB guys. I might even have one, but I take no responsibility if you have it runaway when you fire it up. You can just as easily swap out governor covers in the truck as on the bench, but you must make sure you don't force anything, that could bend the linkage and you could have a runaway situation. You also need to make sure you have that audible click when voltage is applied and removed. You should be able to slide it forward and back a bit very gently and it should have this slight spring loaded action. Just trying to help you do this on the cheap so you get it moved, get the man off of you and decide what you really want to do with this truck. A pump is expensive and personally I would either buy a stock pump from Agnem or find your local Stanadyne shop, hopefully with some good references. If you want to buy online, buy from Uhaul or their ebay site. Also I think Oldbull88 stockpiled a few of those Uhaul pumps. They should be fine. Otherwise online shopping for an IP is risky. I bought an econo online pump when I first got into IDIs and it was a difficult learning experience.

 

[Diesel JD]

I should clarify that the fuel shutoff solenoid is what I refer to as the governor cover, I know there is actually a lot more in there than just a FSS, but I wouldn't recommend anyone compound the difficulty of this procedure by swapping solenoids unless they know their DB2 pumps very well, myself included.

 

[Pele]

I removed the cover and put +12 volts to both solenoids... (I had to ground the cover.) The small one in the back moves a little. The big one that has the arm on it moves a lot.

 

[Agnem]

Here's the thing to try. Just leave the top cover off and try to start the engine. If the pump is getting fuel, it's going to make a big mess, and if it starts, you will have to use your finger on the govenor arm to shut it down, but that will certainly rule out if the top cover has a problem or not.

 

[Pele]

I'm kinda having a hard time understanding fuel flow through this pump...

Fuel enters through the center of the unit and then what?
Are there eight individual pistons to shoot high pressure fuel to each of the injector, or is it just a distributor rotor and there's one high pressure pump?
How does the entire pump fill up with fuel then?


I'm getting fuel out the return port. That's the brass Elbow fitting right on top if I'm not mistaken? I didn't take the fitting out, I pulled the rubber hose off.
That return fitting goes right into the top cover, so it stands to reason that I'll dump fuel all over the place if I crank with the cover off.

I didn't get it at any high pressure, It just came out kinda like it comes out the schrader valve on the side of the fuel filter. Maybe 5-10 PSI... Should I be getting it at high pressure?

 

[Diesel JD]

That all sounds right. The return pressure is pretty low on these engines. The only high pressure you'll see is at those hard line fittings and at the injectors. Low pressure from the tank to the pump and low pressure from the return on the pump and injectors back to the tank. If you're getting return pressure that should mean the pump is working as designed I guess? Now I'm in over my head. The only reasons I have ever seen for a persistent no start like that are a sheared pump shaft or a bad governor cover. It almost seems like this pump wants to work. Also if you're up for trying to understand how the fuel flows through these pumps we had a thread on here that linked to a full factory shop manual. You could dig back through to Friday night or if you want and you can provide an email I will send it your way.

 

[Pele]

So what should I try next? Or should I just bite the bullet and order a new pump?

 

[OLDBULL8]

Disconnect a couple lines right at the pump and see if you get any flow out there.

 

[Agnem]

Next thing would be to take the fuel screw access cover off, and verify with a mirror that when you crank the engine, you see things rotating in there. This will confirm that the input shaft has not snapped.