Injector pump woes

[Texasmark1]

1965 Ford 3000, CAV pump, tractor sits a lot and gets run half an hour or so at least once a month. Starts in a couple of seconds regardless of weather. Fuel is pristine and has PS additives. Was out yesterday, after having sat for maybe a month, fired instantly, then running 2.5 hrs at PTO RPMS, temp tad over center scale, well within white region, 2nd gear out of 8, 6' hog, pretty bumpy terrain and high summer, stemmy weeds, reason for using 2nd gear. Ran like new. Today same thing only for 3.5 hrs. All of a sudden it just eased itself to 0 rpm, slower than it takes to shut down when you pull the fuel shut off knob.

In troubleshooting back at the shop, great fuel flow all the way down to the fuel inlet on the side of the pump....cap is off the tank and in taking it off, no vacuum whishing sound. While crakking, the bleed hole on the pump will squirt clear slugs of fuel past the front tire....3'. Cracked an injector and no fuel there. Scuttlebutt has it that the fuel delivery valve inside the pump....that the governor spring helps to control, gets stuck. I disconnected the linkage to the shut off and the throttle valves, moved both back and forth trying different positions and no response when cranking.

U tube on 100 series tractors, different model of the CAV shows a pin valve that is said to stick frequently on CAV pumps, which is rotated by the throttle linkage supposedly. Said to be a problem when tractors sit a long time. Don't know what a long time is and that's where I am.

I know there is talent onhere. Make my day....grin.
Thanks as usual
Mark

 

[Billy Shafer]

Dieseltech should be along soon. He is the one to talk to.

 

[Tx Jim]

Check to be sure fuel fitting/return line from inj pump to tank isn't clogged. Is fuel tank venting?

 

[caterpillar guy]

Since it was running I would say your deal is not stuck. Starting from the tank checking flow which you said you already did it ran fine. So now if you have not changed the fuel filters do so. Then after bleeding out the filters open the lines or bleeders on the injectors and turn it over till you get fuel out of the injector lines at the injectors will need to be air free fuel. It will probably start or try to by the time you get the air out if you just loosen the lines. Since it died how much fuel do you have in the tank. Yup an inch is not enough. If all this checks out good and still not start try opening the return line and see if that makes it run if so then you either have a plugged return line or bad drive coupling in the pump. If you can't get fuel up to the injectors check your low pressure pump. It may not be putting out enough volume. I would doubt it since it was running already too. If that has the fuel filter with the glass bottom check that you didn't put a seal/o-ring on the top of the filter in that groove. That will stop the flow or could possibly make it not flow enough even though it might look like it is when looking at it.

 

[oldwrencher]

I was told by a man much smarter than I (as most people are) that any injector pump made before 2007 is not designed to work with today's low sulfur fuel andand if I did not add lubrication to the fuel in the 1995 dodge diesel truck that I had at that time I would eventually walk home. Three of my neighborshave had similar though not quite as drastic circumstances as you describe with their tractors and adding transmission fluid to their fuel for pump lubrication solved their problem.My 2 cents worth and worth what it cost. Have a blessed day.

 

[Texasmark1]

On the return line comment by others, fuel in the tank was 6" deep as that was my first reaction.....did I run out of fuel....so I measured it. When refueling I usually leave the engine running to keep an eye on the fuel gauge. Also look inside the tank to see the actual level. In doing so, I can see the fuel swirling telling me that the return line is working.....so I don't suspect that. But since that has been mentioned more than once here, will open it up and check.

I use Power Services gray as recommended on the container when filling my diesel storage 55 gallon sealed drums. Don't know if any lube is included. Surely could be a lube problem as it had run for 3.5 hours and surely would have been running long enough to potentially get internal binding if LSD didn't adequately lube things. Question here is getting lube into the parts of the pump needing lube and will it free up the works. Will entertain just how I might accomplish that and dive it a try.

I think I will add some ATF to the fuel from now on on my older Fords....used to use it on my big cam Cummins years ago....quart/100 gallons.

Thanks for the replies, hope more ideas come forth. Considering what's invloved in getting the pump out of a 3 cyl Ford engine and the hygene requirement of diesel fuel delivery systems, I don't want to reinvent the wheel and in the process introduce a new problem....dirt.

 

[Texasmark1]

Funny, after posting the reply just now, I did a search on CAV pumps and typical problems. A reply came up and the title was: Injection pump too hot.....daaaaaa after 3.5 hours of running under a pretty good load, at 1800-1900 rpm (PTO rated 1800-540) in 90+* ambient temp, engine temp gauge running mid scale, I think you guys were onto the return line blockage as the potential culprit as that was the suggestion from that site too. That helps me to spend considerable time in ensuring that path is open.

That just leaves me with the problem of getting it to crank after I check that out. If it is a built up pressure problem in the return line, that should self fix after the visit. But if something overheated and is stuck down in the pump, then that is a horse of a different color.....we'll see.

Ideas still welcomed.

 

[jacksun65]

I have worked on two fords with cav pumps recently. The 3000 had bad fuel and slowed down and stalled but wouldn't start back up. After replacing fuel and filters flushing the tank, finally figured out all three injectors quit working. Replaced them has been doing great. Ford 5030 Quit in the field running a disc mower, had already flushed the tank and filters on that one 3months before. Changed filters they were full of white sandy looking stuff not sand. I bled the system but couldn't get fuel to the injector line. Took the pump off sent it to rebuilder said the head had sheared off, also rebuilt the injectors two our of four were bad. This tractor had set for a while and this new fuel doesn't do well at shelf life.

 

[Texasmark1]

Got the filters and starter out of the way and had a look at the compressor blades and popped the top and looked at the throttle lever/cam. Output shaft and carbon brushes producing the high pressure were locked to the main shaft as they should be. I got the lid off awhile ago and it seems that the fuel flow paddle/valve that is controlled by the throttle and the counter spring is no longer operated by the throttle. Seems the shaft has stripped out of the arm controlled by the throttle rod. Makes sense. No fuel feed to he high pressure pump with good pressure at the bleed port. Now the fun part begins.....finding the exact part.

Not all bad, I was needing to pull the solenoid off the starter to reverse the contact plate as apparently it had arc'd adequately that it would contact, but didn't always carry enough current to roll the engine. Glad I procrastinated on that task.