JD 4100 starting issue

[Fosti]

I put an amp meter in series with the ground cable to the battery, no drain in the Ma range , put it in Ua range and got a .02 ua reading. . So I don’t see it being a drain and the battery is brand new. Still it will start a few times then I remove the maintainer and after a day or so try it and it just cranks.

 

[Harry in Ky]

I, for one, agree you need to do some experimenting to confirm the operation of the fuel shut off solenoid. Parts book shows what appears to be a three wire circuit. If that's what you have, one will be ground, one will be start and one hold. I would start right there. Figure out which is which, and make sure there is battery voltage to the start (or pull) circuit while starter is engaged. Or you could just remove the solenoid from the pump. Hang it where you can see it while turning the key. See if the rod retracts when you turn the key to start, and stays retracted with key in run position. This should tell you something.

I have a hard time understanding why simply sitting a few days unused causes the problem to come on if the battery has enough to spin the engine over with no problem. If the problem were glow plug related you should still see some smoke while cranking whether it starts or not. No smoke means no fuel, for whatever reason.

 

[Fosti]

All good information, I will try what you suggest .I understand I am here for help and I will try your what you suggest . I am with you on it doesn't make sense for it to happen the way I have described. The battery is brand new and the one that I replaced was old but it held a good charge .The fact that it was 5 1/2 years old and was weak is why i replaced it. That was interesting your comment no smoke no fishing even if it doesn't start.

 

[Cdash]

It is well worth it to purchase the service manual. I was having issues (ended up being a voltage regulator of I recall correctly). The service manual will walk you step by step through the diagnosis. Much better process than firing the parts cannon.

 

[Starbucket]

The only time my tractor failed to start was a dead glo plug. It was getting hard to start for a few mo.s leading up to that. I replaced all of them with NGK and now it starts faster and runs cleaner than ever before.

 

[NYlumberman]

I put an amp meter in series with the ground cable to the battery, no drain in the Ma range , put it in Ua range and got a .02 ua reading. . So I don’t see it being a drain and the battery is brand new. Still it will start a few times then I remove the maintainer and after a day or so try it and it just cranks.

 

[NYlumberman]

I had a 4200 that gave me fits about starting and was advised to change thermistor by a JD dealer. There was fair amount of disassembly to get that done. The issue was that corrosion on the fuse reduced the voltage enough so the fuel solenoid did not pull in. It’s worth a quick check.

 

[hummertom]

I have a 4300, very similar, while I had a similar problem mine turned out to be the fuel pump not developing enuf pressure, but since what you've done indicates electric I would try the following,
1 chk the ground point
2 chk the sockets for the relays in the power centers and the fuse sockets
3 replace all the relays, they are available online for a few bucks each
4 When replacing the relays and fuses use dielectric grease from any parts store

The design of the power center is stupid, it allows dirt and water to get into the back, lastly you may have a battery drain even while off, if so a simple fix is to put in a battery disconnect cheap from TSC.

 

[Fosti]

It is well worth it to purchase the service manual. I was having issues (ended up being a voltage regulator of I recall correctly). The service manual will walk you step by step through the diagnosis. Much better process than firing the parts cannon.

Thanks , I do have a service manual. I purchased one but didn’t seem to find the answer there. I however stumbled on a thought. I had my tractor serviced and when it came back I noticed that the idle seemed to be on the low side , I just figured that is where it should be. It always started but since then I’ve had issues. I bumped up the throttle a bit like 20% and it starts just fine. Thanks to all that have given me directions. I will see if it starts in a week after sitting.

 

[super55]

I am going to go with the fuel shutoff solenoid as well. I could be gummed up or one of the hold-in circuits might be starting to fail.

The solenoid has two circuits to it. One is the hold-in that stays on all the time and the other is a pull-in to help draw the plunger in but eventually shuts off so it will not overheat and burn it out prematurely.

They are pretty common on going out and not terribly expensive. If it is cranking fast then the most likely cause for a non-start is the solenoid. You should hear a solid click as soon as you turn the key to the run position.