# 4600 SU will not start when engine is warm???



## mainstreet (Jun 10, 2008)

I recently purchased a 4600 SU and am enjoying the work it does. The problem is after I have run for a few hours and shut it down, it will not restart for several hours. In the morning it fires right away. It also would not start yesterday afternoon when the outside temperature was in the 90's. Anyone have any insight?


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## Live Oak (Dec 22, 2003)

Welcome to Tractor Forum mainstreet! Sorry to hear of the problems you are encountering. I would suggest starting at the beginning of your fuel system. Check the fuel tank for being propery vented. Most fuel tanks are vented through the fuel cap which can become clogged by insects. Is the tank pickup filter screen restricted? If this tractor uses a fuel lift pump, is it working properly? Is the fuel line between the fuel tank and fuel filter clean and unrestricted? A blast of compressed air will verify this. Are the fuel filters clean? When was the last time they were replaced. Are the fuel lines going upto the injector pump and up to each injector tight and not leaking? Air could be getting into the system. 

Lastly don't discount contaminated fuel. Verify the fuel in the tank is clean good fuel. 

When you attempt to restart the tractor and it will not start.....are you getting good smoke from the exhaust when cranking?


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## mainstreet (Jun 10, 2008)

The fuel line was leaking where the two lines come together near the tank. I got that repaired. I also changed the fuel filter. The Tractor does show good smoke when it is turning over. I have noticed that the lower bolt on the front of the cylinoid gets extremely hot during the period of non-starting that I am dealing with. Could this be an Electrical problem?


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## Live Oak (Dec 22, 2003)

> _Originally posted by mainstreet _
> * I have noticed that the lower bolt on the front of the cylinoid gets extremely hot during the period of non-starting that I am dealing with. Could this be an Electrical problem? *


Do you mean it gets hot just standing static without the engine running? If so, does it do this when you turn the key on or is it continuously?


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## mainstreet (Jun 10, 2008)

No, As I try to start the tractor it gets hot. So hot it can't be touched.


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## Live Oak (Dec 22, 2003)

> _Originally posted by mainstreet _
> *No, As I try to start the tractor it gets hot. So hot it can't be touched. *


You may have some corrosion or other contamination causing resistance to current flow there and this will definitely cause heat. You might want to take that connection apart to check for corrosion, clean it up real good, and reassemble for another start attempt. 

A slow turning starter motor can be a hindrance to a good start with a diesel.


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## Live Oak (Dec 22, 2003)

There may be another cause working here that I sure hope is NOT the case but let's make sure all the basics for a good start are taken care of.

If you are getting good smoke on starter crank, that tells me the engine is getting fuel and air. If the starter is working properly with a good strong battery, we are left with compression. Do you know if the previous owner was using ether to start this tractor?


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## mainstreet (Jun 10, 2008)

No, I do not know but he tells me that the motor was rebuilt only 300 hours ago. I must say, the machine runs great when it runs. In the morning It fires right up and I can run it all day. I just can't shut it down. Well I can if I park it on a hill. It will coast start easily when it is warm.


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## Live Oak (Dec 22, 2003)

> _Originally posted by mainstreet _
> *No, I do not know but he tells me that the motor was rebuilt only 300 hours ago. I must say, the machine runs great when it runs. In the morning It fires right up and I can run it all day. I just can't shut it down. Well I can if I park it on a hill. It will coast start easily when it is warm. *


Doesn't sound like a compression problem since it starts good cold. When it fails to start have you removed the fuel cap to check for a vaccum? 

Have you checked the battery (s) with a hydrometer to ensure there are not bad cells? 

When you are trying to start the engine hot, does it appear to turn over and spin as fast as when cold?


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## mainstreet (Jun 10, 2008)

Initially it seems to turn over just as quickly, then it slows as if the battery is dying. I tried hookig up some jumper cables to my pickup but it make no difference. I never tried starting it with the gas cap off. I will give that a whirl. By the way Thanks for your input.


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## Live Oak (Dec 22, 2003)

If your battery has a short in it caused by one or more of the cell plates warping when they get hot or warm after the tractor running for a perod of time, connecting jumper cables will NOT help. The short circuit created when the battery cell plates short out will consume all of the extra power from the jumper cables. 

It could well be a possibility the battery is the problem. After the tractor sets and cools off, the battery cools off as well as do the battery cell plates and it will start again. 

Have you tried swapping in an known good battery or completely bypass the tractor battery altogether by disconnecting the battery cables from the tractor battery and hooking up the jumper cables to the tractor battery cables?

I have seen a shorted battery behave like this before. Electrical bugs can be tough to isolate.


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## chrpmaster (May 5, 2004)

Good suggestion Randy on the battery issue. Should be easy to check too by switching out the battery or removing the cables and attaching them to the jumpers from your truck. 

I was also wondering about the hot bolt you mentioned on the solenoid. I am wondering if it heating up that much is causing the bearings to expand and bind inside the starter. This would cause the starter to turn slower.

Testing the idea of changing out the battery will tell you which one it is. maybe time to take the starter and solenoid in for a rebuild.

Andy


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## David Flury (Aug 14, 2019)

Mainstreet, did you ever figure this out? I have a 4600 row crop and you are describing my issue exactly.


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## txbrill (Dec 5, 2014)

I think it is the nature of the 4600 I had exactly the same problem on my 4600. I checked everything... over the years I replaced all the filters vents etc. i never figured it out, i did find that if i tried restarting immediately after stalling or shut down it would start right up if i waited even a short time it would not start until i waited a couple of hours, i gave up trying to figure it out, it is a great tractor though


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## Ultradog (Feb 27, 2005)

David Flury said:


> Mainstreet, did you ever figure this out? I have a 4600 row crop and you are describing my issue exactly.


What is a 4600 row crop?
As to the starting problem, it sounds more like an electrical issue than a fuel issue.


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## David Flury (Aug 14, 2019)

Hi Ultradog. 

The row crop is the farming version of the 4600......as opposed to the SU which has a few different features. notably, the SU has the front axle of the 3000 and smaller series.


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## David Flury (Aug 14, 2019)

Partners,

Update..... I finally fixed the issue of not starting after warming up. See the original post from Mainstreet. My issue was a worn injector pump. Not starting when hot is an issue with the head of the injection pump. Pretty expensive rebuild, but totally changed my tractor. It now starts wthin about two seconds hot or cool.

The guy at the injection repair shop said that is common on Ford Tractors with CAV pumps.


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## pogobill (Jan 31, 2012)

Thanks for the update David. Glad you got it sorted out.


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## Ultradog (Feb 27, 2005)

David Flury said:


> Hi Ultradog.
> 
> The row crop is the farming version of the 4600......as opposed to the SU which has a few different features. notably, the SU has the front axle of the 3000 and smaller series.


Glad you got the non starting issue resolved.
As to your 4600 being a row crop...
Small quibble with you there.
The standard 4600 was called the 4600 AP as in All Purpose.
Yes they made the 4600 SU (Special Utility) and also a 4600 NO (Narrow Orchard) but they did not build a 4600 Row Crop.
Ford did build some Row Crops on that platform but discontinued them with the 4000s in 1975.
I have one that I'm restoring.
Here's some couple photos of mine and a dealer ad for one.


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## David Flury (Aug 14, 2019)

Told me something I didn't know. I thought there was the SU which was more of an industrial version and the row crop which was agricultural.


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## Ed Williams (Jun 13, 2019)

Nice photos. I had never seen one with the single front. All I have seen was dual wheel tricycle front. Are the single front common? With a tractor that tall, why do you need a floor jack, it wouldn't reach any jacking point.


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