This engine is in a square shooter SS636. Put a genuine john deere reman engine in with new injectors and i get zero throttle response. But if you grab the joystick & put a load on the engine the injection pump will rev it up to keep the idle rpm. Pinned the engine @ tdc and verified pump timing. Installed new lift pump. Had the injection pump rebuilt at a reputable shop and same problem. I have 3.5psi coming out of the lift pump. Took the pump & injectors back out and took them back to pump shop. I watched them run it through the test procedures on bosch test machine. So at this point I'm wondering what else could be causing this. Anybody have any ideas?
So if you move the throttle linkage at the engine, you get no response? Air/fuel filters new? Any smoke? Have you monitored for any drop in lift pump fuel pressure with engine loaded?
Correct. Move the throttle linkage and get no response at all from the engine. All new filters. I did not look @ lift pump pressure when i tried loading the engine. There was some smoke but i was running this @ night under LED work lights so i couldnt really tell you color or volume well enough to speak to it. Fuel shop told me to try running off a separate supply and route the return into a separate container too. They were thinking maybe a volume problem or restricted return.
Go to the right rear of the fuel tank and pull the fuel line off and it should have good fuel flow. If not unscrew the big hex nut fitting out-there's a screen on it and it can get stopped completely up. Have some buckets to catch fuel because it will really come out of the tank-it's like a ! inch pipe fitting going into the tank. If that isn't the issue and the fuel filter is the type that has the plastic nut that threads onto the filter base check it. I had one develop a small hairline crack that would suck air. I'll bet the screen is stopped up though.
Rag in the intake manifold? check the fuel pressure running first...
Makes no sense unless your engine is at full load already and incapable of more. Something is getting missed.
Pumpguy where are you ?
How about an engine serial number?
Or an injection pump model, even picture. And what happened to the old engine?
Sorry, I clearly forgot some details I did mean to include. thats what I get for trying to hurry old engine serial # is T04039D474697 new # is SE4039D792263. Pump is a stanadyne DB2 #2435-4972. Old engine had ridiculous amounts of blow-by and was just slobbering out the draft tube. would barely run. Vetech I think you're absolutely right something is getting missed. I just cant figure out what. I don't think the engine is already running at full fuel (load) because when I grab the joystick and give it a little bit of a load it does respond. just not with the throttle. tractormech thanks for the tip on the pick up screen. I will check that too. I appreciate all the help guys and I will follow up once I get this back together and retest. If anybody comes up with anything else I am open to more suggestions.
My guess is restricted return.. I woulda told u the same thing.. Run it from a 1 gallon jug(oil) of fuel & run the return into same jug.. Good luck
A check of the fuel supply pump pressure would be in order. I'll bet you will see a vacuum.
Are you sure you dont have a load on the unit when your starting and running and once you stroke a control you change the swash plate and that allows your engine to rev up since you dont have a parasitic load of a hydraulic pump ?
okay here is the follow up. got the pump and injectors reinstalled. We ran it from a separate fuel supply and the return into a separate jug, No change. had plenty of fuel returning from the injection pump into the jug. had black smoke from the exhaust like it was under a load. I guess our next step is going to be to pull the coupler shaft to the hydraulic pump and try again. I'll follow up again later. Thanks again folks
check the shutdown linkage lever on the inj.pump,its the linkage arm on the side of the pump opposite the throttle control lever..sometimes the lever isnt in the full fuel clockwise position and will limit the amount of fuel delivered to the engine regardless of the throttle lever..it'l fool ya into thinking the pump is bad or not adjusted right. I've had a few gensets that use the Stanydyne DB pumps do that to me..wouldnt rev past 1200rpm
Hi guy sorry to jump into this later on but does anyone have a workshop manual for Deere 4039DE engine. Much appreciate the help. Having the same issues as above but I suspect the injector pump is done.