4020 Hot Start

ShaneC · Dec 8, 2010

We have a 1968 4020 that after it runs for awhile does not not want to start again! I"ve talked to several people and they have experienced the same problem. Any suggestions?

tim s · Dec 8, 2010

I've seen this happen before, it could be the starter,,or the injector pump, I had an injector pump act this way and if the owner would pour the water jug on the pump it would start, we ran the pump through the pump shop and that fixed that one...

Heavyduty1 · Dec 8, 2010

I know when mine was hard to start when hot, I replaced all the battery cables with (0) cable from a big truck parts shop. I have the dual 12V conversion on mine, too.

Tx Jim · Dec 8, 2010

May also be a hyd caused problem which moving steering wheel side to side while cranking or putting a destroker screw in hyd pump could help.

tomstractorsandtoys · Dec 8, 2010

I will agree with Tim it is a pump problem. Try dumping cold water on the injection pump, if it helps your head and rotor are shot inside the pump. We had a 2240 do the same thing years ago. Running the tractor generates heat which causes expansion, With a bad pump after warm up fuel will not pump correctly causing the tractor not to start when warm. It will run fine after starting. It is not a good idea to dump cold water on a good pump as it could cause it to seize up.

JDemaris · Dec 8, 2010

Diesel I assume? Is it cranking fast but not firing when hot, or is it cranking slow when hot?

As already mentioned, a worn head & rotor inside an injection pump will start fine cold, run fine hot, but not restart while hot. One work-around is - sometimes - just to get it cranking a little faster. When a head & rotor gets worn and the tractor won't start hot - it's mostly about slight leakage at slow cranking RPM. Sometimes all it takes is getting it to spin another 100 RPM faster. Bigger batteries, destroker in the hydraulic pump, etc.

Also, sometimes turning up the fuel-delivery screw 1/8 a turn clockwise can make up for wear and make it start better again.

David G · Dec 9, 2010

Had the same issue, rebuilt pump.

Heavyduty1 · Dec 9, 2010

(quoted from post at 00:36:33 12/09/10) Diesel I assume? Is it cranking fast but not firing when hot, or is it cranking slow when hot?

As already mentioned, a worn head & rotor inside an injection pump will start fine cold, run fine hot, but not restart while hot. One work-around is - sometimes - just to get it cranking a little faster. When a head & rotor gets worn and the tractor won't start hot - it's mostly about slight leakage at slow cranking RPM. Sometimes all it takes is getting it to spin another 100 RPM faster. Bigger batteries, destroker in the hydraulic pump, etc.

Also, sometimes turning up the fuel-delivery screw 1/8 a turn clockwise can make up for wear and make it start better again.

Where is the fuel-delivery screw on the pump?

4020 Hot Start

ShaneC

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tim s

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Heavyduty1

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Tx Jim

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tomstractorsandtoys

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JDemaris

Well-known Member

David G

Well-known Member

Heavyduty1

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