4020 Fuel Troubles

Unless the injection pump has been rebuilt, its past time for it to have failed. There's a plastic governor ring that comes apart and plugs the fuel return line. And that keeps it from getting fuel to run good, so I hear.

Replacing the lift pump is way cheaper than rebuilding the injection pump, but neither is beyond suspicion.

Gerald J.

A diesel 4020 will run without the lift pump working once the system is primed; if there is much fuel in the tank; at all 'cause the diesel pump has it's own primary pump. MAYBE not at full HP; but it SHOULD at least rev up.

In that respect the diesels are different than the "gassers".

While something COULD be clogging the lift pump; the lift pump on his diesel is low on the list of the causes of the problem he's having.

Low on the list; but still a possibility.

Whether or not the lift pump lever "feels" like it's working is determined by where the fuel pump cam is when the engine stops.

90% chance your problem is caused by the plastic governor damper ring in the IP beginning to fail; causing plastic "coffee grounds" to plug the IP's housing pressure regulating valve/fuel return fitting; #29 in the drawing.

Of course; something clogged in the SUPPLY side COULD be the problem; as well.