Fuel Injector Pump leaking

[erps]

The engine is a Universal M4-30. The injector pump is not pumping

Was this all of a sudden or was there a degradation in performance? Did you troubleshoot the fuel supply lines to make sure it wasn't sucking air somewhere? A lot of fuel delivery problems with diesels are associated with not getting the fuel to the injector pump in the first place. I have my fingers crossed for you that you injector pump is not the problem.

[ADwight]

There was a degradation in performance. I knew air was being sucked in but could not find the source. I had replaced all fuel lines some 8 weeks previously and all was well, and then uneven revving up and down for some time and then sudden death. No restart. Found I had good fuel pressure up to the pump, but none after the pump. In removing injector lines I discovered number 3 fitting (don't know the proper term, but it was the 3rd fitting north that line was attached to) was loose, not screwed down tight. Vibrated loose, maybe? That's where air was being sucked in. Removed pump yesterday and today learned that of the four cylinders or four pumps that make up the pump, the two center ones are froze up. It's my understanding that if air or water gets in the
cylinder or shaft, the tolerances are so fine, that without the constant lubrication of the diesel fuel, the plunger will become scored and freeze up.
I learned today that I need to clean the housing thoroughly with an air compressor, like pressure wash it thoroughly to remove all grime, work in a dust and dirt- free room on a clean surface (like white freezer paper), remove the side panel and go in and see what I can find and then go from there.

[ADwight]

Ray, thank you for your response. I am also communicating with a shrimper who knows diesels and am learning as I go. I see the problem as a challenge and as an opportunity to become a better sailor. It's my first serious issue with the engine in my boat, and I want to learn everything I can so that I can keep my engine running well and can get it running again when it stops. There is much to learn.

[CalebD]

You can try rebuilding the pump but Erps doesn't think that you will have much luck. I hope you do.

You can also look up the Kubota engine block # as in: History of the Universal Motor Company 4

From the link: "The Model M4-30, also called the Atomic Four diesel, a 52 cu in, 25 hp, 4 cylinder, based on the Kubota Y-850 block, was built from 1988 to 1997. Approximately 470 were sold. The Model M4-30 was offered as a diesel replacement for the original Atomic Four gasoline engine. It was similar to its namesake, since it was a 4 cylinder model weighing slightly less (122 kg / 270 lb as opposed to the original’s 150 kg / 330 lb with reduction drive - the M4-30 was only offered with a reduction drive) and generating slightly less power (18.6 kW / 25 hp at 3,600 rpm as opposed to the original’s 22 kW / 30 hp at 3,500 rpm) with a smaller displacement (850 cc / 52 cu in as opposed to the original’s 1,065 cc / 65 cu in)."

The point I am not making is that with the Kubota engine block number AND a tractor model you can find the same pump for a lot less at a Kubota dealer. Maybe not the same exact pump but it will work for a good while.

[erps]

There was a degradation in performance. I knew air was being sucked in but could not find the source.

I just went through something similar this spring. My motor was taking a long time to get started. It was losing its fuel prime. I also had fuel weeping around the top of the injector pump. It turned out to be the o-rings around the fuel injector nozzles. I was able to repair it without removing the pump by just pulling each fuel injector barrel, replacing the o-ring and a little copper washer gasket. I got lucky. We have a very knowledgeable diesel pump repair shop in the area who told me it was a common problem with old Volvo diesels.

[ADwight]

Thanks to you both for the great information. Am about to begin dismantling the pump. If no interruptions I hope to know more soon.

[ADwight]

The pump is pretty much dismantled and in pieces. Found 3 broken springs in 3 of the 4 chambers, and still have the head pieces of one of the plungers still up in the chamber, stuck. Will have to find tiny needle-nosed pliers to get a hold of it and try to pull it out (tweezers don't grab tight enough to get a good hold). Soaking in diesel now. Wanted to give update to those interested. Am thinking that if I can find the proper replacement springs, and if the head pieces of that stuck plunger are not damaged, and if I didn't score or scar the chamber walls removing the parts, and a few other "ifs", then I just might be able to put this thing back together and make it work. Any information on replacement parts or rebuild kits, etc. would certainly be welcome. Thanks.

[PorFin]

Dwight,

You may want to think about first using compressed air instead the needle-nosed pliers -- much less likely to scratch/score the bores...

[ADwight]

Thanks, Erps. I got the plunger unstuck by removing top of chamber and going in from the top. I placed a socket on the stuck plunger head and tapped it lightly and it dropped out the bottom of the chamber. Order four new springs from a diesel injection specialist shop, who informed me that my particular pump does not have a rebuild kit. He said he could not quote me a price to rebuild it because he would have to take it apart and see what all it needed. I replied that I've already done that and there are 3 broken springs. He said he would have to do it himself in order to quote me a price. He said I was asking for trouble because the pump would have to be calibrated after being rebuilt. I asked how much that would cost, and he said he couldn't say because he would have to rebuild it himself in order to calibrate it. He said I would have to take certain measurements according to the specs (which he said there was no way I could get) in order to attempt to calibrate it. I can't see where any measurements of any kind are called for. All the pieces go back together again in only one way, the way they came out. I don't see anything to measure or calculate. Am I missing something crucial? I ordered four new springs from him anyway which were 8 dollars apiece, and freight was $20.00 more from Wisconsin to Florida. Am I asking for more serious engine damage, as he said, if I put the pump back together and reinstall it without paying him an unknown figure to rebuilt & calibrate it?