BearKiller

An acquaintance has a 1989 D-250 5-sp, bone stock except for a couple hundred thousand miles.

Like most, it always has fired at the first touch of the key.

Test light shows the solenoid has fire to it.

The truck can sit for overnight, or a few hours, and start easily.

But, if it sits for two nights, without being started, it will crank and crank, but no start.

When it does this, work the hand lever, on the lift pump, for a few strokes (the strokes have little resistance, like not much is going on), and it will then start and is good to go, so long as it doesn't sit for more than overnight.

I have an old gas-burner that used to act like this, and it turned out to be some sort of "check-valve" in the carburetor that was letting the gas drain back to the tank.

There are no noticable fuel leaks that I can see.

I told him I would put it before the experts and see what you guys had to say.

Thanks.

1stGen545

Sounds like the lift pump. Mine dose the same thing but has a huge leek in the Injection pump ( more going on the ground than threw the injectors.)

wannadiesel

Yep. Throw a lift pump at it.

BearKiller

The engine runs strong as always.

Just how quick is the pump going to quit and strand the truck??

He wants to know does he have a few weeks to gather the necessary parts to do the piston-pump, while still using the truck??

He probably averages a couple hundred miles per week.

I guess when this happens, there will be THREE piston-pumps ordered and installed.

Thanks.

wannadiesel

If the truck's staying stock just get a standard replacement lift pump on there and forget about it.

Chrisreyn

BK, one other thing to check is the fuel heater seal.
When I was having a similar problem, it turned out that i had slightly loosened the fuel heater when I changed the fuel filter and it would loose prime if it sat for several hours.
My lift pump handle has very very little resistance, but when cracking the line to the filter from the LP, I could see it was pumping fuel..

ppiggppenn

My LP was acting up some time ago and I decided it was quicker to stick an electric pump along the Dvrs side frame rail as a temporary measure. Well it's worked so well that my new LP is still in the box waiting for a day when I wanna get real greasy. I run it off a relay that runs my clearance lights and fuel solenoid so I never have to think about it. Further when I got some watered fuel I was able to pump most of it out conveniently by hot-wiring the elec LP and catching the fuel under the removed fuel filter.

BearKiller

I have wondered, is the fuel-heater simply screwed on like a fat fuel-filter spacer??

If the fuel-heater were removed, would the filter screw on where it came off, thereby eliminating the heater??

Thanks.

Chrisreyn

The heater is the black " spacer' between teh block and the filter. It screws onto the same stud that the filter does. the stud is larger going into the block and the heater "rides" on a shoulder on it... it then narrows, becoming the filter stud...
There is a square shoulder O-ring between teh heater and the block.
I dont think you could remove it, the filter snugs up to it...

If you remove the filter and look "up " at the stud, you'll see it either is grooved for a large screwdriver or some newere ones were "keyed" for a large hex-head.. this is how to remove/tighten it...

BearKiller

I am seeing two seperate part numbers for standard lift-pump.

#3928143

#3904374

Which is correct, if either; or, are both correct??

Thanks.

Palerider

Theres a filter in the tank that will get plugged up over time and would cause the lift pump not to be able to pull up the fuel sufficiently (cavitation).

wannadiesel

I don't know, but I wouldn't spend Cummins money for a diaphragm pump. Get this one.

http://www.usdieselparts.com/moreinf...name/Feed_Pump