CAT 416 Injection Pump Lucas CAV DPA

[NewGuy416]

CAT 416 Backhoe
*5PC01199* 9R0001
Engine: U081907N 2W9777

LUCAS CAV Injection Pump
3343F740
17537BDG


I just bought this 80's CAT 416 Backhoe that will only run on ether. I've been troubleshooting the fuel system since we parked it a couple days ago. The seller I bought it from is a diesel tech - said he took the injection pump off, cleaned out some sludge and threw it back on. Still didn't start and got too busy to stay with it. Then I came along and made it my problem and bucket of fun.

As far as I can tell now, everything's in time. After wrenching her over enough times, idler gear and injection gear are lined up. Then, looking through the plate window, I see "C" lined up with that little indentation. All this looks how I think a properly timed pump should for a mechanically governed 4 cylinder pump (I think).

I've got the suction pump hand priming fuel past both filters and all the way up to the inlet on the injection pump. Can't get any fuel out the pumps vent screws, or up and out to any of the injector lines.

Verified the solenoid works out of the pump, it has continuity from keyswitch, and even trialed running separate 12V to keep it open while cranking engine. Still no high pressure fuel.

Took the cover off the Injector Pump
"How Pump Was Setup" (photo)
Spring was connected to the lowest hole on left connection and the nearest hole on the right (I believe that’s wrong, should be middle, right?)

However after freeing up the shutoff lever "Pump Lever" (photo) which was stuck on that misaligned tab, I put spring back on as I found it (had a real tough go trying to get spring in middle slot on the right side).



Summary:
Fuel getting past lift pump, past both filters and up to the inlet side of injection pump, but No Fuel through bleed screws on injection pump, and nothing out injector lines.


My only current thoughts on next steps:
Check screen on inlet side of pump.
Could that spring position be enough to stop all fuel flow?
Send in to one of the IP specialty shops for recondition.


Any advice on what I could still be looking for or am I to the point where we know the problem is in the pump, but experience says let the pump pros recondition it?

Thanks for reading!
Sean

 

[NewGuy416]

These 2 photos didn't upload originally

 

[Cliffy]

Looks like its had a gut full of water by the surface rust inside the pump.

 

[Welder Dave]

The spring under the cover is extremely important it's in the factory position. It's common for the lift pump to need replacing on a Cav. pump system but the pumpguy would be the best one to give advice on what could be wrong. With the pump numbers he might be able to tell the correct placement of the spring. It does seem odd a diesel tech. didn't fix it before selling. Maybe he knew there was a bigger issue?

 

[thepumpguysc]

If u have fuel all the way to the pump inlet & have the bleeder screw open BY THE NAME PLATE and the solenoid is operational, & nothing coming out of the b screw.. your pump is locked up..(seized)

 

[NewGuy416]

If u have fuel all the way to the pump inlet & have the bleeder screw open BY THE NAME PLATE and the solenoid is operational, & nothing coming out of the b screw.. your pump is locked up..(seized)

Thanks. Going to send it off Diesel's Fuel Injection Service in NH for a rebuild.

 

[reganj]

Ummmm, I believe @thepumpguysc may be able to help you, He has already provided guidance for you and did an excellent job for me as well as many others.

 

[thepumpguysc]

Thanks, but I’m going under the knife and clearing out what I have here now and turning away work as it is…
Won’t start back up until the end of August..
Nothing serious, just some eye problems.

 

[Welder Dave]

Hope everything goes well for you. My partner gets shots in her eyes every month or two and they are helping. I can't remember what condition she has.

 

[ianto36]

We had that with Caterpillar 428 here in UK turned out it was a stuck metering valve not allowing diesel into chambers