John deere 4020

mark in HC KY · May 13, 2009

I have a 1971 model 4020 that has been restored and switched from manual fuel pump to electric. I purchased it this way, and it does not seem to want to start, the batteries were running down and we replaced them and the alternator. it takes a long time to start, alot of cranking and the battery usually runs out of juice before it starts. does anyone have any ideas?

Rick in Michigan · May 13, 2009

Sounds to me like the electric fuel pump is not developing enough pressure. There was a reason the Roosa's were so expensive to rebuild.
I'd try going back to the original.

tjdub · May 13, 2009

Had the same problem with my dad's 4020 diesel. It would never start without a shot of Ether. Turns out you need to rebuild the motor every 12,000 hours or so

Bob · May 13, 2009

WRONG answer. If the fuel tank is half full or above the tractor will start and run and work WITHOUT a lift pump at all. If the electric pump is working AT ALL, it is NOT the problem.

Bob · May 13, 2009

Does it start right up with a little whiff of ether? If it DOES that would point to timing problems and/or a worn out engine.

If it DOESN'T smoke as soon as you begin cranking it and start right up with a whiff of ether, that would point to fuel system problems.

What injection pump does it have... it could either have the good old Roosa DB series pump or the little Roosa "C" series pump which is sort of a "red-headed stepchild" in is not supported well by Stanadyne these days, although there are supposedly NOS parts around for diesel shops that know where to look. Even if it came new with a "C" pump, many were changed over to the "DB" pump later in life.

The pump should have an ID tag, with model number.
Here's what the "DB" series looks like:

<img src = "http://www.waterstractorparts.com/images/pages/21-13.jpg">

Rick in Michigan · May 13, 2009

Gravity feed only works on a GASOLINE engine. Diesel's need high pressure to the injectors.
...then again, I am just guessing it's a diesel.

Anonymous-0 · May 13, 2009

If your console 4020 has never had the motor updates, then it needs the new piston and ring combo to up the compression. Much better starting and much better performance. Refer to your dealwer for info

twopop · May 13, 2009

I think you missed bob's point.if the fuel level is above 1/2 full the lift pump is not necessary because the fuel will flow thru the electric pump and keep the injection pump full.by the way,there are actually 3 pumps on a 4020.lift pump,vane pump in inj.pump head and high pressure pump in the inj. pump center

Don-Wi · May 13, 2009

Not true. The later model 55 series Oliver's eliminated the lift pump and are gravity flow to the injection pump. We have an 1855 that is that way, and it runs fine.

We even have auxilary fender fuel tanks on it and it has enough vacume in the main tank to draw from the fender tanks. I have also heard that if I were to shut off the fender tanks and leave the non vented cap on the main tank, it would crush the tank from the internal vaume.

Not all deisels need to have a lift pump installed. Maybe it's cause ours is an Ollie.

Donovan from Wisconsin

mark in HC KY · May 13, 2009

I have never tried ether, cause i dont believe in it. however the engine was rebuilt within the past 100 hours. how hard would it be to change out the electric fuel pump and put another type of electric pump?

buickanddeere · May 14, 2009

It could be the rest of the "rebuild" was a "cobb job" as the fuel pump addition.
If the cylinder head work consisted of grinding the origional valves and seats then doing nothing else. The engine isn't going to start worth beans. They just took away the compression required for starting.The rest of the "rebuild" may have consited of just rings and bearings too.
If that fuel pump is wired to run when ever the key is turn on. Then leave the key in the on position for 5 second sbefore cranking the engine.
Here is a question that not a single person has answered in 7+ years of asking. What is the voltage at the starter motor while cranking? This will tell use much of what we need to know.
If there isn't a hydraulic pump detroker. Spend the price of a a pack of smokes and install a detroker.

John deere 4020

mark in HC KY

New User

Rick in Michigan

Member

tjdub

Member

Bob

Well-known Member

Bob

Well-known Member

Rick in Michigan

Member

Anonymous-0

Well-known Member

twopop

Well-known Member

Don-Wi

Well-known Member

mark in HC KY

New User

buickanddeere

Well-known Member

Similar threads