1979 B7100 Fuel Injection Pump Rebuild

[BackYardWrench]

Symptom: Cylinder 3 would not fire.

Cause: Injection pump plunger worn and could not deliver sufficient pressure for injector to fire during compression. Tractor did not have fuel filter in fuel line. Recent new to me acquisition so I do not know how long tractor ran without filter.

Solution: 1) Buy new pump - I did not get price; 2) Buy used pump $350 with one year warranty; 3) Have pump professionally rebuilt - Cost $650-750; 4) Rebuild pump myself.

I chose option 4. Trying to get cylinder 3 to fire, I swapped injectors and delivery valves with no success. So I took injection pump out and apart. Being careful to replace parts the way I took then out, I was able to swap plungers for cylinder 3 with cylinder 1. The plunger swap now caused cylinder 1 not to fire and I found my problem.

This is a Diesel Kiki pump. Here are all of the numbers off of the pump tag: D860674 NP PFR3KD50/2NP4 License Bosch Assembly No 4293-300 15381-51011. Diesel Kiki changed its name to Zexel under a Bosch license, I think. I got my parts from Bosch. Three of each: delivery valves, delivery valve springs, copper crush washers, plungers and plunger springs. Cost with tax was $418.

Bosch used the 15381-51011 number to pull up the current parts list. The current Zexel pump number is 104293-3001 and the Bosch pump number is 9 410 617 013. I have the parts schematic and individual part numbers if anyone needs them. One little caveat: when I got my delivery valves and plungers, they appeared way bigger than the ones I pulled from the pump. After much consternation and consultation with Bosch experts, Bosch opened a plunger and they were an exact match. The thick protective plastic that the plunger was encapsulated in and its plastic bag only made it appear bigger.

The pump rebuild does not require any special equipment and involves only the installation of delivery valves, plungers and springs in a clean environment. The only spec is the delivery valve holder torque which is 32 ft/lbs. There are no shims that need to be calibrated like with an injector.

The other part of the assembly that needs careful attention is the control sleeve, which has a notch and that notch/mark must line up with the timing line/mark on the control rack. I've attached a pdf of the marks.

 

[D2Cat]

Man, you make that sound as easy as rebuilding a single handle Dela faucet!!

Keep us posted, with a picture of black smoke belching at fire-up.

 

[Jim L.]

OK, the figures you posted have me curious.

Where did you find the documentation for your pump? Was it from Bosch, or did you already have access to manuals? Or did the parts list include setup instructions?

 

[BackYardWrench]

Jim L the attached images come from a document that is posted on this website.

 

[Mudball]

Good luck with getting the parts in and hope it goes as well as your rebuild.
Look forward to reading or seeing the results.

 

[Trent]

Nice write up Barckyardwrench! I'm new to diesels, you can help me understand something.

What is the best way to know which cylinder is firing?

On gasoline engines, my mentor Bud Echols would pull plug wires off one at a time. Never saw him flinch.

Thank You, Trent

 

[kcw12]

I would put about a quart of power service and quart of marvells mystry oil in it, crack the line and hope for a little fuel to go through it.

 

[rentthis]

Trent, loosen fittings at the injectors one at the time. If the engine stumbles, that cylinder is firing. When you come to one that doesn't cause stumble, that one is dead.

 

[BackYardWrench]

Appreciate the encouragement! My B7100 ain't pretty. For years, she was doomed to a spot under a tree and then became a parts tractor. My first task was to weld the plugs on both ends of the cam - posted in another thread. Also pulled the head and replaced the head gasket.

I'll post short videos of it running, hopefully, tomorrow.

Trent: Im new to this as well and trying to catch up to speed. And all disclaimers apply - do this at your own risk!! These are four stroke engines so the piston goes up twice. My flywheel has marks - 1Fuel Injection Timing which is slightly before 1TDC, second mark. Cylinders 2 and three have similar markings on the flywheel. There is a plug about 1 and 1/4 inches in diameter on the right side (looking forward on the tractor) of the bell housing.

Not sure what you are after... if its the valve adjustment, its very easy. Put engine at 1TDC and you can adjust both intake and exhaust of cylinder 1 AND the the exhaust of cylinder 2 AND the intake of cylinder 3. Rotate 360 to cylinder 1 overlap and adjust Cylinder 2 intake AND Cylinder 3 exhaust and you are done. You will know if Cylinder 1 is at top dead center as you will have valve cover off and both valves will have some play. In overlap, one of the valves of Cylinder 1 is under pressure. If you are starting out on a fresh engine, you have to align the marks under the front cover. You can also visually see where piston 1 is with the head off or by pulling the injector.

I attached the page for the valve adjustment procedure with just two rotations. It covers two cylinder, three cylinder and four cylinder engines.

 

[BackYardWrench]

The injection pump rebuild went without a hitch. She now fires on all three cylinders. Pump also holds pressure as it starts as soon as I hit the starter, less than one rotation. I attached some photos and short video (videos giving me a battle so upload later).

I tried to take a picture of the worn plunger alongside the new one to show the wear from all of the unfiltered fuel. Unfortunately, the photo is with my phone and the quality many not show the wear that is apparent to the naked eye. The worn plunger tip is the one on the right.

Not all is 100%. My injectors did not come so I used the old injectors and there is smoke. I have good compression so hoping the injectors resolve the smoke to nice black puffs with over throttle.

 

[coachgeo]

The injection pump rebuild went without a hitch. She now fires on all three cylinders. Pump also holds pressure as it starts as soon as I hit the starter, less than one rotation. I attached some photos and short video (videos giving me a battle so upload later)...

Glad to hear.

You might have to load vid. to Youtube, Vine orrr? and then put a link to it here. Where ever you post it make sure the settings allow for others to view it.

 

[ar1g3]

Just brushing the dust off this thread to say thank you! You saved me a lot of work and money by posting the numbers and pdfs on here!

 

[ar1g3]

I will again revive this thread, now with a question. After waiting ages for parts to arrive I'm now finally rebuilding the pump. Upon reassembly I found that the punch mark on the control sleeve is missing. So I have no reference to align it with the control rack. Guess it has worn off.

Anyone any idea? Does it line up with the V notch with which you align the plunger? Not keen on finding the correct timing by trial and error as you may understand...

 

[North Idaho Wolfman]

There has to be a mark on the gears or you can not align it.
Take some pictures of the top and bottom of the gears.
I've done quite a few of these pumps and have yet to see one without the marks.

 

[ar1g3]

There has to be a mark on the gears or you can not align it.
Take some pictures of the top and bottom of the gears.
I've done quite a few of these pumps and have yet to see one without the marks.

No mark visible on mine. But there is some kind of brown/yellow marking on one tooth of each gear. Thought it was maybe bit of rust but its on the same tooth on every gear, and directly opposite of the v notch for plunger alignment. Seems to not be a coincidence.

Photo of the yellow mark:

 

[North Idaho Wolfman]

Yes that is the mark to align to the notch in the rack.

 

[ar1g3]

Yes that is the mark to align to the notch in the rack.

View attachment 110597

Ah wonderful! Thought it should be a punch mark, and that this was maybe just random discoloration or rust as the pump has been sitting in a spare parts box for a long time.

Thanks a lot for confirming that!

 

[2drx4]

Does anyone have a link to the full manual that a few pages of are posted in the OP?

I looked on Kubotabooks and didn't see anything that should be it.

 

[Tailboard]

Hey all...I hope this post gets seen by you guys.

I have a 1990 Kubota D950 (aka marine Universal 25XP) with what appears to be a Zexel 3 port high pressure pump. I have 3 broken plunger springs and found rust on what was labled 020 and 220. I have found a "fuel injection pump rebuild kit" but don't have a source on who to talk to...Kubota? Zexel? Universal? Your posts were so helpful, and the pictures were great too. Any input would help. 2 pictures attached.

 

[North Idaho Wolfman]

Hey all...I hope this post gets seen by you guys.

I have a 1990 Kubota D950 (aka marine Universal 25XP) with what appears to be a Zexel 3 port high pressure pump. I have 3 broken plunger springs and found rust on what was labled 020 and 220. I have found a "fuel injection pump rebuild kit" but don't have a source on who to talk to...Kubota? Zexel? Universal? Your posts were so helpful, and the pictures were great too. Any input would help. 2 pictures attached.

Just clean the rust off of that part it's not a tolerance or surface critical part.
Get new spring.