Colt Case Ingersoll Garden Tractors

thebuildist wrote: ↑Mon Jun 24, 2024 8:10 pm Well, now I've had the privilege of tearing down and (hopefully) re-assembling an injector pump.

I didn't enjoy it. My British friends would call it "fiddly." Very fiddly.

I couldn't find precisely the correct manual or video for it, but I watched a couple that were consistent enough that I was able to apply the knowledge to this one.

It turns out that each of the 3 "pumping units" are actually small (5/32" or so) precision ground pins reciprocating inside precision honed sleeves. The pin is the piston, and the sleeve is the cylinder.

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The pin has a vertical slot (think keyway) and the sleeve has a hole in its "cylinder wall" near its midpoint. So if the pin is rotated to a certain position in the sleeve, then the "keyway" slot can draw fuel through the cylinder wall hole, and with each stroke a bit of that fuel will be "pushed" upward to the injector. But if it's rotated to a different position, then the keyway is away from the hole in the cylinder wall, and no fuel is pumped.

So the volume of fuel is controlled by rotating that pin.

The pin is indexed inside a gear-toothed collar.

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And moving the control rack rotates that collar.

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So sliding the rack rotates the pins, which causes them to pumpeither a little or a lot of fuel.



But those 1 inch long pins sitting in those 1 inch long sleeves, with maybe a thousandth of clearance were very solidly glued in place. They couldn't move up or down, they couldn't rotate. So the geared collars couldn't rotate, so the rack couldn't slide.

I had to drive the pins down out of the sleeves with a punch. (Delicately). Cleaned everything up, washed it in gasoline, lubed it all up with wd-40, and reassembled everything. Now the pins reciprocate and/or rotate freely. Rack slides effortlessly.

It'll probably be Thursday before I can put it all back together and confirm it pumps when the engine turns over.

Assuming it does, I expect to have a runner!

Bob

DavidBarkey wrote: ↑Tue Jun 25, 2024 6:05 am Well done Bob . I found a place in UK that sell rebuild kits for small deisel injector pumps . I plan on doing the Kubota 2 cyl. in the bride before firing it up.