Home Forums Hunting & Shooting Hunter's Campfire Diesel mechanics? Help me out

The pressure of gravity is a variable so the pressure of a full tank would be higher than an almost empty one, seems to me that some kind of fuel pump is a necessity even if it is a mechanical part in the engine as opposed to an electric tank mounted unit

You’re a smart ‘Cat. You should know better than listen to dustcunt.

Check for debris inside the fuel tank. ( a leaf, paper towel... ) I had the clear cellophane wrapper off a fuel filter block the outlet port once. SOB died on the freeway. It would fire back up, then slowly die. It was hard to see even with a flashlight. drove me nuts until I found it.
Something is restricting the flow of fuel....

Will you explain to him there is no pump in the system beyond the injector pump, that multiple of us, including the OP, have discussed as potentially coming apart clogging the return line? He isn’t comprehending. Maybe I type to fast?

Actually an injector pump is a fuel pump that regulates the pressure. Anyone tried injector cleaner, or tested the pressure at each injector to test for the correct pressure to each cylinder

This. Air trapped in the high pressure lines to the injectors will cause foaming and stalling.

According to the post there are no high pressure lines, just gravity feed

Exactly how do you call a Roosa Master a pump and the Stanadyne pump a wannabe? They are the same pump (in this case probably a DB2), made by the same people, in the same building, on the same equipment, in the same town (was Windsor, CT; until manufacturing was moved in 2011).

FYI: Roosa Master & Stanadyne are the same company, with the original company name being Hartford Machine Screw (HMS).

The issue with the pump is that the governor retaining ring has deteriorated over the years and the pellethane material (RING MATERIAL) has broken up and pieces of it are beginning to block the return on the pump. As the pressure builds up inside the pump, the engine will stall due to a no fuel delieved condition caused by high housing pressure. With the engine off, pressure will subside, the material falls back into the governor housing, unblocking the return and allowing the engine to start again....until the crap is picked back up and re-blocks the fuel return. the best bet it is you have the pump rebuild. You can do it yourself, but make sure you have the tools needed, and beware that if you break anything you might be SOL, as some of the parts are becoming obsolete (cam pin screw & removal tool on some of the older DB pump is a big one). Also, I don't remember if the Allis pump has a face cam on it, and if it does make sure you mark its position before removing it.

If you decide to pull the pump, make sure you have the engine timed correctly, typically TDC. Also be-careful cleaning the inside of the pump, particularly the head & rotor as they are a lap fit clearance, into the millionths of an inch (the do not touch each other even though it looks it and they require a film of fuel on each other at all times).

There is a hack work around, but in time you will only hurt the pump and it performance and I suggest not doing it.

The Standyne pump works fine on a gravity system as the DB pumps do have some sucking abilities, though a mechanical or electric lift pump is preferred.

I'm having a similar problem in my Kubota tractor. I'm pretty sure it is a fuel problem and replaced one of the two fuel filters and will be replacing the second one tomorrow. After talking to the mechanic at the Kubota dealer this morning he was saying something about sometimes a small piece of debris like a pebble or something will fall in the tank and block the fuel line so the fuel can't be sucked out by the fuel pump or in your case by gravity in sufficient amounts to keep the engine running. After he said they were a month out on repairs and it was a four hour ticket to remove the fuel tank I decided this is one I'll be fixing myself...

Not is this case. Engine runs then stalls, then will re-start. If there is air trapped in the lines the engine will die and not re-start until the air is bled out. It won't keep starting and stalling.

The OP that there is no fuel pump just a gravity system. Seems that someone really does not know what they are looking at

I stole these picks off google as I no longer have access to my old engineering R&D pictures.

New Pellethane retaining ring:

What is left of a governor ring:

Reading comprehension isn’t your forte is it?

The OP talked injector pump.

I talked injector pump.

Flint Locke talked injector pump.

45_100 talked return line blockage which is typically a failure of injector pump components.

Then you respond that you can’t believe there isn’t a fuel pump….Maybe in the tank or something and it’s blocked….

The only discussion of gravity was about lines to the injection pump. Which, we all know, is a pump. “Injection pump”. It has the word pump in it. Pumps build pressure.

Good luck to the OP. Sorry for muddying up your post.

Sackett, maybe just a bad run of luck, but the old original RoosaMasters on John Deere elec gen sets would get 25 to 30,000 hours service. After the overhaul, I replaced the old RM's with Stanadynes, (same OEM part group number, direct fit) not all, many failed at 8 to 14,000 hrs. I'm not a pump guy, but it made me wonder. Stanadynes on 580 Case backhoes fail pretty frequently too. But, about the same time, EPA changed #2 diesel specs to get a cleaner burn so maybe that was a factor.

Most diesel engines with a Stanadyne rotary fuel injection pump have a mechanical or electric fuel pump that will supply fuel to the Stanadyne pump, typically around 5psi. The older Deere engines have mechanical lift pumps that look identical to a Delco unit on a small block chevy engine to supply fuel under pressure vto the DB pump. The newer Deere engines have electrical supply pumps in the tank. I believe other companies such as Allis & older Ford's used gravity to supply fuel to the Stanadyne fuel injection pump.

LOL, actually if the injector pump failed the unit would not start at all.

Try again Mr. Nuclear

The low sulfur fuels of today suck with regards to lubricity, which a rotary pump needs (standyne & lucas). Not trying to push a product, but the standyne performance formula additives do work and they are OEM approved.

What are they failing for? Seizures? Or the same issues the Op is having?

This applies to vehicles used on the roads, both diesel and gas. Note part D. Since the OP is talking about a farm implement, none of this necessarily applies.


§ 393.65 All fuel systems.

(a) Application of the rules in this section. The rules in this section apply to systems for containing and supplying fuel for the operation of motor vehicles or for the operation of auxiliary equipment installed on, or used in connection with, motor vehicles.

(b) Location. Each fuel system must be located on the motor vehicle so that -

(1) No part of the system extends beyond the widest part of the vehicle;

(2) No part of a fuel tank is forward of the front axle of a power unit;

(3) Fuel spilled vertically from a fuel tank while it is being filled will not contact any part of the exhaust or electrical systems of the vehicle, except the fuel level indicator assembly;

(4) Fill pipe openings are located outside the vehicle's passenger compartment and its cargo compartment;

(5) A fuel line does not extend between a towed vehicle and the vehicle that is towing it while the combination of vehicles is in motion; and

(6) No part of the fuel system of a bus manufactured on or after January 1, 1973, is located within or above the passenger compartment.

(c) Fuel tank installation. Each fuel tank must be securely attached to the motor vehicle in a workmanlike manner.

(d) Gravity or syphon feed prohibited. A fuel system must not supply fuel by gravity or syphon feed directly to the carburetor or injector.

(e) Selection control valve location. If a fuel system includes a selection control valve which is operable by the driver to regulate the flow of fuel from two or more fuel tanks, the valve must be installed so that either -

(1) The driver may operate it while watching the roadway and without leaving his/her driving position; or

(2) The driver must stop the vehicle and leave his/her seat in order to operate the valve.

(f) Fuel lines. A fuel line which is not completely enclosed in a protective housing must not extend more than 2 inches below the fuel tank or its sump. Diesel fuel crossover, return, and withdrawal lines which extend below the bottom of the tank or sump must be protected against damage from impact. Every fuel line must be -

(1) Long enough and flexible enough to accommodate normal movements of the parts to which it is attached without incurring damage; and

(2) Secured against chafing, kinking, or other causes of mechanical damage.

(g) Excess flow valve. When pressure devices are used to force fuel from a fuel tank, a device which prevents the flow of fuel from the fuel tank if the fuel feed line is broken must be installed in the fuel system.
[36 FR 15445, Aug. 14, 1971, as amended at 37 FR 4341, Mar. 2, 1972; 37 FR 28752, Dec. 29, 1972]

Tell that to everybody that has a flex ring starting to come apart, obscuring the return line back to the tank, and has a tractor doing exactly as the OP has.