980b fuel problem

What engine would a 980 have? The D337F on our DW20 has an injection pump with no side covers like the older ones had, so no access to the rack that way.

It was also stuck in "shut off" and we were able to access one end of the rack on the governor end I believe by removing a cover there.

We were only able to get a small prybar/big screwdriver in there and move it back and forth and it didn't want to free up enough for the governor to control it until we began turning the engine over and working it back and forth at the same time. This is probably because the pump plungers were the problem more than the rack, so moving them up and down as well as twisting did the trick.

We had the injector lines loose on all cylinders at the time!

With that serial # it would have a pc 3306T with sleeve metering fuel system.

[quote="superdog"]a friend of mine has a 980b loader 89p6618 serial # we were told it ran 2 years ago but judging by the fuel its most likely longer. we cant get any fuel out of the injection pump going to the injecters. there is fuel to the primer pump because you can olny pump it 2-3 times and it gets hard.i cant find any transfer pump on this machine is it internal in the injection pump? we made sure the throttle pedal was depressed before we tried starting the loader. anyone have any ideas or suggestions? i thinking the rack in the injection pump may be stuck in the no fuel position. which covers on the pump should i remove on the pump to look? i forgot to mention that we drained the fuel tank and refilled it with clean fuel and changed the one fuel filter that we could find.
thanks steve.[/quote]

hello
your engine arrangement should be 4n7377?
fuel transfer pump is in housing on injection pump on drive end.have to pull pump to replace. open pet cock on side of pump and pump priming pump till fuel runs clear from tube then crank motor and see if you have a good fuel flow from tube.if you have a gauge fuel pressure sould be about 30 psi. if fuel seems ok bleed injector lines.suggest you get service book for pump before you open pump housing.plate on side will acess pump rack.may have water filter also.
good luck Bob

My sometimes right source says it would be a 3306 (3N) engine.

Take the big plate off the side of the fuel injection pump and see if the plungers are moving up and down. They may be stuck. If they are moving up and down, make sure the metering sleeves are free to move up and down.
Later Bob

This would be a 3N 3306.....2P6812 engine arrangement....no side cover on injection pump.

This would be a 3N 3306.....2P6812 engine arrangement....no side cover on injection pump.

89P6618 makes it a 1977 model, and it's definitely powered by a 4N arrangement, 3306 engine. According to all my info, it most certainly should have the sleeve metering fuel system - and the sleeve metering fuel system has a big removeable sideplate on the pump which allows you to inspect the internals.

superdog - the sleeve metering fuel system is a whole lot different kettle of fish to the old Cat Scroll system.

The sleeve metering system is a pressure-type fuel system.
The entire pump body is full of pressurised fuel, and the sleeves, plungers and camshaft operate fully immersed in the fuel.
The plungers are raised and lowered by the camshaft, similar to the old Cats .. but the amount of fuel injected is governed by sleeves that slide up and down the plungers.
These sleeves cover and uncover spill ports to adjust the amount of fuel injected.

There is no rack, as in the old Cat Scroll pumps, that turns the plungers to adjust the amount of fuel injected - the sleeves are operated by a sleeve control shaft with levers bolted to it .. which is connected to a bellcrank .. which is attached via a sliding collar (flyweight follower), to the governor flyweights.
The throttle control lever sets the sleeve positions, and the governor, via the bellcrank, adjusts the sleeve positions (fuel delivery rate) according to load/RPM.

The fuel transfer pump is not really "internal" or "integrated" as such .. but it is located on the front of the pump body, sandwiched between the pump body and the accessory drive. You need to remove the entire main fuel pump body, to remove the fuel transfer pump.

Here is a scan of an excellent little booklet that outlines the operation of the sleeve metering fuel system .. there are 8 pages, and you can save them, and print them off, if you require paper copies to study ..

Page 1 - http://img375.imageshack.us/img375/6212/sleevemetering1.jpg

Page 2 - http://img375.imageshack.us/img375/4253/sleevemetering2.jpg

Page 3 - http://img375.imageshack.us/img375/2373/sleevemetering3.jpg

Page 4 - http://img375.imageshack.us/img375/9308/sleevemetering4.jpg

Page 5 - http://img375.imageshack.us/img375/2191/sleevemetering5.jpg

Page 6 - http://img375.imageshack.us/img375/4782/sleevemetering6.jpg

Page 7 - http://img375.imageshack.us/img375/3869/sleevemetering7.jpg

Page 8 - http://img375.imageshack.us/img375/2268/sleevemetering8.jpg


Bob's advice is correct. Old fuel gums up fine tolerance components .. and if you pull that side plate, and check that all the plungers are going up and down O.K. .. that the sleeves and the sleeve control lever are working fine, without jamming in the linkages anywhere .. you're off to a good start.

The sleeve metering fuel system has to be completely air-free to function properly. Loosen the injector line nuts on the pump body, and open the manual bleed valve.
Loosen the bolts that hold the torque spring or stop bar cover (the small cover plate with 3 bolts between the governor and the main pump body). This releases any air in the governor housing.
Once you are certain all air is out of the system, tighten the stop bar cover bolts, the injector line nuts, and the bleed valve.

There should be an electric shutoff solenoid on the pump. Actuate the shutoff, and you should hear a clicking sound. If you hear clicking, but the engine still won't start .. unbolt and remove the solenoid, and try to start the engine again. If the engine fires, the solenoid is faulty and needs to be replaced.

The transfer pump should supply fuel at 10 to 20 psi at cranking speed. If this pressure is less than 10 psi, the transfer pump needs to be replaced.
Make sure you have good fuel flow from the tank to the fuel pump, by removing the fuel line at the pump completely, and checking for a good stream of fuel.
Some of these Cats have a small mesh primary screen in the line, mostly near the pump, and this can be a source of fuel restriction. Check the parts book for this, if you have one.