John deere 4300 fuel trouble

Ironmower · April 28, 2009, 06:51:40 AM

Our 4300 fuel solenoid will work sometimes and other times won't. I replaced it twice, and still the same thing. Then the dealer sold me a $3.00 thermistor ???, They said it popped up on their computer that this was the problem :

The only problem is they can't tell me where it goes :( What we've been doin' now is; takin the fuel solenoid off and clean the oil out of it, then it will work for a while :

Once the tractor is started it runs fine, the problem is only when you shut it off (for lunch) it won't start till I clean the solenoid out again >:( What a pain. HELP ??? ???

isawlogs · April 28, 2009, 08:16:35 AM

Reminds me that I have an intermiting probleme with our car , sometimes it will crank over for but not start , turn key off and then try again and it will start with half a turn of the starter ... :

Nissan Sentra '03 Our dealer told us to bring it in when it wont start , :

Yep that'll be real easy to do .

Your dealer can't " Phone Home " to find out where your mistory part goes .... ??? Seams to me they could give head office a buzz and have an answer to that real quick .... Then again some aintreal quick to begin with .

isawlogs · April 28, 2009, 08:23:44 AM

I went fishing to find out what a thermister was :P found this and copied it for you

" I think the new solenoids are made alittle differently so this doesn't happen any more. If I remember correctly, there is a groove in the side of the plunger so the oil can get past. You also may have a thermistor that is failing. The thermistor controls how long the pull-in windings of the solenoid stay engaged. It is located behind the fuse panel. Pull the fuse panel out and cut out the old one and then solder in a new one. It is part number LVU10323 and is alot cheaper than a new solenoid. It is a small square orange device about 3/8" square. We call it a "chicklet" (gum). Maybe I am showing my age, do they still make "chicklets"? "

pineywoods · April 28, 2009, 08:56:58 AM

Sounds to me like an electrical problem. Borrow a voltmeter and check the voltage on the terminal of the solenoid when you turn it on. Should be pretty close to 12 volts. If not, trace the wire run back to the switch that activates the solenoid. Somewhere there's a voltage drop. If there is a thermistor in the circuit, that would be a prime suspect. with less than 12 volts applied the solenoid would be rather marginal.

beenthere · April 28, 2009, 10:29:28 AM

Ironmower
What is the part number on the thermister?

Do you have a tech manual for the 4300?

You may have found the problem already with pineywoods and isawlogs help.

beenthere · April 28, 2009, 11:25:06 AM

Ironmower
Here are three images I picked out of the 4300 tech manual. From the discussion, it may be a clue to where the thermister goes. Fits with what Isawlogs found.

Fuel shutoff relay location on fuse block

Schematic with thermister shown.

Drawing showing fuel shutoff relay and thermister location.

This R2 thermister and relay apparently allow an initial high current to flow and then cuts the current flow after the solenoid opens. If more explanation wanted, I can copy what it says in the manual.