M 1009 Fuel/Bleeder Delivery Issue.

[68fbjjz109]

I am in the process of acquiring a 1985 M1009, The truck is mechanically and electrically (still 24V) sound and somewhat recently made a 10 hour trip from VAto PA to be stored while the previous owner redeployed to Alaska.

When driving the truck, it stalled and left us on the side of the road. The previous owner was planning on replacing the fuel filter, so that's where we started.

Still would not run.

Replaced the Mechanical Fuel pump, primed the fuel system off the barb by the filter bleeder valve with a vacuum pump. The truck would start, run, and idle well. When we crack the Bleeder on the filter assembly to ensure that all air was out of the system the truck would shut off. We did this two more times with the same results, regardless the of the engines RPMs.

Is this normal?

Now my friend and I are not light wheel vehicle mechanics, or GM Diesel guys. He however is a Benz tech, and I am mechanically inclined.

We feel that when we crack the bleeder valve while the truck is running fuel should should emerge under some pressure as the pumps seem to put out about 5psi. I know the IP is capable of pulling fuel from what i have read here; which is how we feel the truck is running currently. We are a little out of our element, and cant find a similar issue posted online to reference. We don't want to risk damaging anything as we are trying to get it ready for daily driver duty.

We have a new diesel electric pump that we can use to bypass the mechanical pump, however we would both prefer to leave it mechanical for the time being.

Thanks

 

[markg]

Welcome to the site. has the truck run with the new lift pump installed? it should run with the bleeder open and a stream of fuel almost hitting the inner fender(after bleeding air ). if sounds like you have a fuel pressure problem. i would verify the installation of the lift pump, including the pump rod. if thats good check for trash in the fuel return fitting of the injection pump. also check the filter base for leaks. thanks. mark

 

[doghead]

And the rubber lines and fuel pickup.

 

[68fbjjz109]

Thanks for the welcome. Prior to posting we pulled the mechanical pump twice to verify the rod was in the correct position, which was far from enjoyable even with grease holding the rod.

The truck will start and run, and sounds normal. We haven't tried to drive it as it will stall when we open the bleeder on the primed system. So even though it seems to run just fine we don't want to risk damaging anything.

From what we can tell there are no noticeable leaks in the system, so well check the return line, and sock filter in the tank.

 

[markg]

If the truck starts and runs, does it rev up? if it boogs when you give it fuel you either have a fuel supply problem or a restriction in the pump. third, check the obvious, air supply? you will find it. thanks. mark

 

[68fbjjz109]

Well we put the electric pump in and no issue bleeding the system properly with appropriate fuel pressure. However it seems the starter solenoid on the 3 month old reman starter went bed, as it disengages rather abruptly. Hopefully that can be addressed and we can put the m1009 back on the road.

Edit:
Swapped in new starter, had an Gen 2 charging issues turned out to be the Gen 1 bulb followed by the Gen 2 bulb. Took it on a 65 mile trip to Philly, wipers which didn't previously work, started working.

Success finally.