Well this one has me stumped.
I have three N/A Injection Pumps that I am trying to clean up to sell. I got one fired up right away by using a jar and two hoses and a drill to spin it round and round.
One pump is toast! I don't have any idea why the inside of it looks like it does because I bought it for cheap on Craigslist. Wasted my dime there. It is reddish, flaky, bubbly stuff that does not even wipe off with diesel. So that one is not going to get any more love from me.
The last pump is the one that is making me write here. I was able to spin it up and get fuel out the top of the OUT bolt and return to the jar. Granted it had lots of little bubbles in it but I expected that. The one working pump did as well. I removed the delivery valves off the back of the pump and verified they were stuck shut so I freed them up and tried again. Nothing, not a drip not a squirt. I removed one of the valve bodies altogether and it spits out like no tomorrow.
So what might cause the pressure internally to be so low that the valves are not opening to let it out?
Is the pump not cycling back and forth enough? I verified that the collar and throttle mechanism is all in place as it should be. Actually did that three different times for different thoughts on the matter.
Might the pump be plugged? Hmm, didn't check that, but with the delivery of fuel out the back without the valve in place I think at least one hole is working correctly. Maybe I need to pull them all off and see.
What are your thoughts on this matter? Where would the restriction be? Where would I be losing pressure?
Let me know, I have spent a couple of afternoons soaked in diesel now and still have no solution. So looking for ideas I have not tried.
Later, thanks.