Oil & Fuel JD 4200 fuel line question

[Mighty Dodge]

My 4200 started fine the other day after sitting for a week. I ran it a couple of hours plowing snow, shut it down for lunch. Went out, no start. I figured water must have been stirred up in the tank and settled somewhere. I put the heat gun to the fuel pump, fuel filter assy. etc., drained some fuel from the tank. It started, ran fine the rest of the day. Went to start it today, guess what, no start. Drained the sediment bowl filled it with diesel 911...no start. Got out the heat gun again, that's when I noticed something. The fuel line runs from the tank to the fuel pump, which is the lowest point in the fuel system, then to the fuel filter assy. It seems to me that it should go through the fuel filter/sediment bowl first so any water doesn't settle in the fuel pump. Is this a design flaw? Seems backasswards to me. I did get it started after applying the heat gun...again. Sorry for the long winded story but has anyone else had this problem with any of the 4X00 series tractors?

John

 

[Wagtail]

My 4200 started fine the other day after sitting for a week. I ran it a couple of hours plowing snow, shut it down for lunch. Went out, no start. I figured water must have been stirred up in the tank and settled somewhere. I put the heat gun to the fuel pump, fuel filter assy. etc., drained some fuel from the tank. It started, ran fine the rest of the day. Went to start it today, guess what, no start. Drained the sediment bowl filled it with diesel 911...no start. Got out the heat gun again, that's when I noticed something. The fuel line runs from the tank to the fuel pump, which is the lowest point in the fuel system, then to the fuel filter assy. It seems to me that it should go through the fuel filter/sediment bowl first so any water doesn't settle in the fuel pump. Is this a design flaw? Seems backasswards to me. I did get it started after applying the heat gun...again. Sorry for the long winded story but has anyone else had this problem with any of the 4X00 series tractors?

John

My 4105 runs a YANMAR 3cyl also (just a wee bit more 'oomph' in mine)... fuel from the tank down to the sediment bowl first, then onto the filter/pump/injector system.

Here's a pdf manual that includes your YANMAR 3TNE78A diesel. The fuel system is on page 3-3: https://fermer.ru/files/v2/forum/132049/servicemanualtneseries1ocr.pdf

 

[CADplans]

My 4105 runs a YANMAR 3cyl also (just a wee bit more 'oomph' in mine)... fuel from the tank down to the sediment bowl first, then onto the filter/pump/injector system.

Here's a pdf manual that includes your YANMAR 3TNE78A diesel. The fuel system is on page 3-3: https://fermer.ru/files/v2/forum/132049/servicemanualtneseries1ocr.pdf

Here is a pic of my 4105.
The line at the far lowest left in the pic comes from the fuel tank.

I just got my 4105,,, it did not like starting,, THE FIRST thing I did was drain the entire fuel system.
Then I installed new filters,, and then filled it with fuel that was strained with a MR Funnel.

Now, at any temp, the Yanmar starts right up like it is a new gas engine.

If I EVER have starting issues again with a diesel,,,
ALL the fuel in the tractor will be drained and replaced first.
The fuel is constantly recycled to cool the injection pump, from what I have read.
These engines burn so little fuel, a complete dump and replace might be worth while occasionally.

 

[Egon]

I've got a JD 4200 with the same problem. Fuel system drained & filters changed, new solenoid and still the same thing. Works fine for a time and then does not start. Heat gun & pumping the primer work to get it started but are no cure.

There may be a Thermistor involved but I have not been able to find it. One dealership said no thermistor, another sold me one?

I have no idea?

 

[CADplans]

I've got a JD 4200 with the same problem. Fuel system drained & filters changed, new solenoid and still the same thing.

If you have a fuel/water separator,, it would be easy enough to re-route the fuel through the separator prior to the fuel pump.

On later JD tractors with the Yanmar engine,, JD did exactly that.

AND,,, get a MR Funnel.

I thought I was OCD over my diesel fuel,,, until I got a MR Funnel.

That funnel showed me that I was a slob dumping water into my tractors.
It was enough to get me to completely change the way I handled diesel fuel.

 

[Mighty Dodge]

I was thinking thermistor, but it only acts up below freezing temps. I think a little water settles in the fuel pump. I'm also thinking about re-routing the lines through the filter assy., then to the pump as the other posts show.

John

 

[Mighty Dodge]

Ok, I'm thinking of re-routing the fuel line to the filter/sediment bowl assy then to the transfer pump. The fuel filter assy is about 4 to 5 inches above the bottom of the tank. If I route the fuel line to the filter first and the fuel level in the tank gets below the level of the filter do you think the transfer pump will pull the fuel through or will I need to lower the filter assy so it gravity feeds to the pump? I realize if I add additive to the fuel I may be able to keep it water free but if I happen to get funky fuel and the temps are below freezing I'll be back to square one. I'd like to make a permanent fix. I've attached a pic. The fuel line in yellow goes to the transfer pump (green) then to the filter (red). As you can see any water is going to get trapped in the lines/pump at the low point.

 

[Egon]

My 4200 is independent of temperature. Happens in the summer too.

 

[Bavarian]

If I remember right, my 4200 had only one filter. It sat in front of the fuel pedal, pretty much sure as the lowest point of the system. Had to shut down the handvalve when I changed the filter.
It definitely sat before the lift pump.
I never had trouble with it. If it was colder than -10F, the operator didn't want to turn the key.

I can't take pictures anymore, I've sold the tractor a year ago and still miss her.

 

[beenthere]

Bavarian
You are right, that the filter does "set before the lift pump", but the fuel line runs from the fuel tank, past the filter and first to the lift pump, then gets fuel back to the filter.
bt