JD650 Fuel Issue

rrobinson87

New User
A very long winded story short... I have a JD650 2wd, it has been sitting outside for at least the last four years. Brought her inside, removed the fuel tank, drained the junk from the system, completed cleaned, refilled, and primed. Cleaned out the intake, cleaned the intake heater, did a valve adjustment just to be safe (not much adjustment was needed). Put a new fresh battery in it, new ground cable. After all that was said and done, I went to start it, it seems I am getting good compression. At first when trying to start it puffs smoke and wants to take off, then it peters out and just cranks indefinitely like Im not getting fuel. Went back and cracked the lines at the injectors, hardly drops coming out. Rebled the system to be safe, same result again. Pulled the injection pump thinking maybe I had some gunk in it, or a broken or seized spring. Nothing. Everything seems fine inside it. Put it back on, reprimed again. Same result. Took the lines completely off downstream of the injection pump and when I crank it over, only droplets form at the top of the injection pump. Hardly enough in my mind to do anything. I expected geysers of diesel to shoot out of it when I cranked. Suggestions, ideas? I dont want to just instantly condemn an injection pump. I have rarely seen them go bad, and when they do I usually see that diesel leaks out the back and into the case and thats where your pressure goes. But this one is baffling me.
 
"I expected geysers of diesel to shoot out of it when I cranked."

That little 17HP engine only burns a gallon of fuel an hour at full load, how much do you expect the IP to deliver in 30 seconds or so, of cranking?

That being said, the injection pump consists of two independent "jerk pumps" and NO transfer pump, so if it's properly bled and the rack isn't stuck (or not properly connected to the governor) it SHOULD pump fuel. NOT much to go wrong besides the "rack" needing to be in the position it needs to be to allow the plungers to deliver fuel.
 
Small PFR type pumps are hard to bleed BECAUSE they don't move much fuel at full load, as Bob said. What I do to make bleeding easier is remove the glow plugs if engine has them to remove cranking pressure, for a bit more speed. With lines loose at injectors, crank until there's good fuel shots at each injector. Then tighten the lines and crank again until air/fuel mist blows out each glow plug hole, which then verifies injectors are getting fuel into each chamber. When fuel is present, install the plugs and start engine. This is assuming the pump rack is not stuck, meaning no pump plungers are stuck.
 
Only problem in this is that the 650 does not have glow plugs. Same as our 750 it uses an intake heater which burns diesel fuel.
 

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