JD 4020 won't run

Neil R · Dec 26, 2009

Bought this 4020 was running rough, put power service in fuel, started running really well then died. Starts but has no throtel response. Has good fuel flow to pump, cleaned injector tips, fuel filters are clean. What is the matter with it?? Any ideas??

flying belgian · Dec 26, 2009

How do you know fuel filters are clean?

Anonymous-0 · Dec 26, 2009

I have a 4320 that ran kinda rough like it was missing on one cylinder or something.I had just bought it at an auction and didn't know much about it except it seemed to start good. It died one day shortly after I bought it and so we changed the fuel filter and it ran perfect, no miss or anything for a short time. Then it started running worse and then it got to where it would run a little and then it would die. I had it running and loosened the bleed screw on the pump and it started running perfect and when I tightend the screw it died again. From all that I am reading the pump has a bad flex ring and needs to be rebuilt, so maybe you are having the same type problem. It could be your pump going bad. Hope you get it fixed, I need to get mine fixed also.

Bob · Dec 26, 2009

ASSUMING that this is the big Roosa IP, remove the complete fuel return fitting/check valve/housing pressure regulating valve from the IP's cover and see if there's remains of the plastic governor damper ring jammed in there. (Will look like coffee grounds.)

You can even try to start it with the fitting out as long as you accept the responsibility for any hazard associated with some diesel leaking out.

If it runs that way, either the valve/fitting is clogged or something else in the fuel return system all the way from there to the tank is restricted.

If there's "coffee grounds" in the fitting/valve a pump OH is needed.

olgentdc · Dec 26, 2009

Bob hit it on the head , Fuel return line was plugged on my 4020 and it sure made me anxious some 15 yrs ago .. has not played that trick since ..

Anonymous-0 · Dec 27, 2009

If you don't fix the pump soon, it could loose governor control a let the engine run away. A rod through the side of the block from turning 6000 RPM has a certain detriment to the value of the tractor!

Gerald J.

Neil R · Dec 27, 2009

filters are new, return has good flow
???

olgentdc · Dec 27, 2009

I would think its time to pull the pump then ,, there is a great mechanic in seymour IN ,

JD 4020 won't run

Neil R

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flying belgian

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Anonymous-0

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Bob

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olgentdc

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Anonymous-0

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Neil R

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olgentdc

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