Re: [MV] multifuel injector problem

From: DDoyle9570@aol.com
Date: Sun Feb 24 2002 - 08:45:00 PST


In a message dated 2/24/02 8:35:10 AM Central Daylight Time,
MVTrucker@aol.com writes:

<< My M35A2 has been sitting for quite a while and will not start. I found
that
 the
 linkage on the side of the injector was stuck in the off position >>

Joe,
I may be able to help you with this....a copy of TM 9-2910-226-34 Pump, Fuel
metering and Distributing is handy too.
I will start at the beginning, just so I (hopefully) won't omit anything.
In the center of the top of the hydraulic head of the pump is a plug, it is
surrounded by the fuel distribution lines. Remove the plug. Stand a soft
wood stick up in the hole, and turn engine over while watching stick. The
stick should hop and down, but since you are having a no start condition, it
probably won't (If it does, we have other issues to discuss). Remove stick,
and spray solvent and penetrant in this hole.
Take out two screws and remove the engine shut off cover and gasket. Verify
that the cable from it to handle on dash moves freely.
The remove the two screws you have just exposed that hold on the Control Unit
Retainer (a sorta U-shaped bracket)...if I remember correctly these screws
are safety wired.
Remove the Control Unit Retainer, then slide out the fuel control unit
assembly. Take care that the small, precisely made, friction fit, T shaped
piece of metal on the inner end of the shaft doesn't get lost. It is the
plunger sleeve pin, and that is what all this is about.
Apply generous amounts of solvent, penetrating oil, etc., to make sure all
these pieces are free to move. Once free, spray with lube.
Reassemble fuel control unit into injection pump, being sure to orient the
plunger sleeve pin properly, it should all slide together smoothly and
precisely, like reassembling a gun. If you think you need to force
something, then you have put something together wrong.
Now, using a brass or similar punch, as close in size to the hole on top of
hydraulic head, rap the plunger a time or two.
Repeat test with stick.
You may have to repeat the penetrating oil/solvent/pecking/stick test process
several times before the plunger moves freely.
The above steps 90% of the time solves this problem. Occasionally however
the delivery valve sticks. This is access by removing a plug in the SIDE of
the hydraulic head. Usually this plug is funny looking (12-16 points), older
engines this plug is hex shaped.
Beware, with the way the pump is oriented in the truck, the delivery valve
and its spring will want to fall out onto the ground, chassis,
whereever....this would not be good as these delivery valves are precisely
matched to the hydraulic heads. So you won't replace just this tiny valve,
but rather the entire, expensive hydraulic head.
Using aerosol solvent/penetrating oil, make sure that the delivery valve is
not sticking.
Reassemble all the things we have discussed.
Truck should now start. However, any time I have fooled with the injection
pump, or a truck that has not been started in a while, I prefer to remove the
air intake mushroom, and have a helper stand by with steel plate or piece of
plywood to shut off air flow in the event the engine tries to run away, or
the shut off won't shut down.
Hope this helps,
David Doyle

copyright 2002, David Doyle



This archive was generated by hypermail 2.1.4 : Mon Apr 08 2002 - 00:24:37 PDT