CAV-DPA Pump Problem. Ford 445A

I bought a 445A with a injector pump problem. CAV-DPA pump. There’s no fuel exiting the pump head. Upon further exam, the engine was replaced with a late edition BSD 333 (New Holland logo cast into the block.). The prior owner’s mechanic took the cover off the top of the pump. I have no idea what he did other than as stated below. The fuel tank is covered with a layer of rust, all the way to the fuel cap. The PO drained some or all of the fuel, installed a new Napa fuel filter, added Seafoam to the fuel and directly to the injector pump after removing the cap. I can crank the engine and get fuel to spurt out the bleed screw on the side of the pump (transfer pump is working???) but there’s no fuel exiting the pump head at the injector lines. The metering valve moves freely and the shut off lever is indexed properly with the shutoff shaft. My guess, from seeing a little discoloration on the shut off lever, is there was water inside the pump. I could remove the metering valve and see if there’s crud blocking the fuel passage but I don’t see a lot of other options besides tearing down the pump. I’d appreciate any suggestions offered.

Fuel spitting out the bleed screw indicates that the transfer pump is working, which means the pump rotor itself is spinning. If you're sure
the metering valve is not stuck, then I'm going to guess that the pump plungers are stuck, which would require disassembly.

Xs two what Bern said, most likely rotor plungers are stuck.

I think you inadvertently just identified the problem.... Do you still have the NAPA/WIX filter on it? And it only spurts fuel, not shoots it
out the bleeder? Just get rid of the Wix filter and put a FleetGuard/NH filter on it.

Beyond that, I would also argue the pump plungers are stuck. However for 5 bucks I'd change the filter first.

Rod

Thanks to all for the info. I remember the problem with the NAPA filters but assumed fuel at the bleed screw was ok. I'll install a new filter first and see what happens. My avoidance of the tank problem is a bit idiotic but was hoping to figure out if the pump would make pressure before addressing that issue.

As much as I hope a new filter will make a difference, I have a feeling the problem is in the pump head. I'll pull the metering valve out and check it before I remove the pump. Can the pump plungers be freed up with reasonable care or is this something best left to someone who rebuilds these things for a living.

Update. Haven't had time to work on the injection pump until this weekend. Pulled the pump apart to see if I could get it working before addressing the rusted fuel tank issue. My biggest problem was the flyweights. They shifted before I saw how they were installed so I struggled with them for a while. Got her back together Sunday and installed on the tractor this afternoon. Tractor runs great. I've been wanting to take one of these pumps apart for 20 years and figure out what makes them tick. Too bad I waited so long.

I'm glad you got her running..
If you would, please tell us how you removed the cam ball from the cam ring..
& the transfer pump rotor from the end of the head, to access the plungers..
I get pumps all the time "torn down" by "regular folks" & NOT ONE will tell me how they did it..
I've been doing this for 30 years & always had "the tools"..
I've HAD TO make a rotor tool once & have HAD TO lock a cam ball in a vise once to remove it.. seeing the previous person "rolled" the end of it w/ an adjustable wrench & the tool wouldn't work..
I'm very curious..& it might help others..

(quoted from post at 02:22:47 09/27/17) If you would, please tell us how you removed the cam ball from the cam ring..
& the transfer pump rotor from the end of the head, to access the plungers...

Click to expand...

I didn't take the pump head apart. Yes I tried to remove the cam advance screw with a crescent wrench to get the cam ring out to make it easier to install the flyweights but I quit before being assessed a tax on stupidity. I could see my attempt was going to end badly before I rounded off the head of the screw. I didn't remove the transfer pump rotor from the head because I could hear what I thought might be the plungers moving (clicking) when I turned the rotor in my hand so I decided to stop there in case I was ahead and before I started going backwards.

It never dawned on me that the transfer pump rotor needed to be removed. I was going to mark the position of the fuel adjustment ring and have at the plungers from the front of the pump rotor but didn't have an 8mm 12 pt socket and wanted to put the pump back together before three weeks passed and I forgot what I was doing. So, I got lucky. Yes, I have a lot to learn before I tear a pump head completely apart and there's tools to purchase. If this pump fails tomorrow I'll still be happy. I got to do something I wanted to do for a long time. Any way you slice it, it was going to cost me at least $500 to send it to someone who knows what they're doing. I don't believe I destroyed anything in the pump so I don't think I'm out any more $$$ if she fails again.

I don't know if anything I did is going to help the next guy as I'm not really sure why the pump works now and didn't before. The PO's mechanic opened the top cover. When I put the top end back together, I installed the shut off rod a little differently than it was when I first opened the top cover. What I did seemed correct to me. When I inspected the metering rod it looked ok to me. There was some discoloration inside the pump but nothing that would affect the metering rod. The transfer pump bypass valve seemed ok. The spring at the bottom of the bore wasn't broken. The plungers sounded like they were moving. Maybe the rollers were making the noise I heard but I don't think so. I didn't change the Napa fuel filter. The transfer pump made more pressure after teardown than it did before. Makes no sense unless the filters weren't properly bled. Maybe I should have paid more attention to the filter body first. That's about it. Probably just got lucky in spite of myself. Fortunately this is a hobby for me and not something I make a living off. Thanks to all for their input. If you know of a source for CAV tools and genuine parts, I'd appreciate a phone number. Thanks. Mike.