JD 4100 starting issue

[Fosti]

Ok so I have read so many post about the JD 4100 starting issues and still having trouble with mine.

So what I have done so far was replace the glo plug relay several months ago and it started just fine . Now I have another starting issue, I checked the specific gravity of the battery with a device that measures it and found it to be weak even after charging. I replaced it with an Interstate 425 CCA 51 battery . Fresh battery starts just fine. A few days later it cranks over fine but won’t start. I put battery maintainer on it and wait for awhile and it starts. Put an amp meter in series with negative terminal and no Ma but I get .02ua draw. That’s not significant as far as I know.

I am lost , seems to turn over nicely, , don’t know what else to check. Thought possibly starter drag but it seems fine. I thought about removing the starter to have it tested .. looks like removing the starter will be a little tricky, kinda sandwiched in there. Any suggestions?

 

[beenthere]

Welcome to TBN
Don't know if this model has the thermistor that lurks in some of the models, but others will likely know better.

 

[Fosti]

If it did , how would that account for it starting with maintainer . Thermistor is strictly temperature sensitive device, I don’t really know how it effects the startup.

 

[Fosti]

Welcome to TBN
Don't know if this model has the thermistor that lurks in some of the models, but others will likely know better.

I don’t know if this model has it, can someone verify that it does?

 

[Fosti]

Either do I and I know from experience it’s not easy to remove the cover under the steering wheel. The steering wheel has to be removed, and some parts to actually remove the cover to expose the components.

It would be helpful if someone here has done this and can actually say there is one before I rip it apart just to find out there isn’t one. I have read if you leave the key on for several minutes then that circuit is actually bypassed but that doesn’t seem right either.
Thanks for chiming in though.

 

[Fosti]

Welcome to TBN
Don't know if this model has the thermistor that lurks in some of the models, but others will likely know better.

Just did a search for that thermistor and they list them for 4200 through 4600 . No mention of 4100

 

[RjCorazza]

Have you confirmed that the fuel shut off solenoid is working reliably? That would cause a crank but no start condition.
I have no experience with your particular tractor, but a fuel shut off solenoid is common to most, if not all, modern diesels

 

[jyoutz]

I had that tractor for 20+ years. The only time I had no start problems was with a weak battery. I suspect that you have a battery drain issue somewhere.

 

[Fosti]

Have you confirmed that the fuel shut off solenoid is working reliably? That would cause a crank but no start condition.
I have no experience with your particular tractor, but a fuel shut off solenoid is common to most, if not all, modern diesels

Well I have not done that as of yet, considering if I leave the battery maintainer plugged in it starts every time. The battery was on the weak side but still cranked extremely well, I decided to replace the battery with a new one. Did not resolve the issue. Thanks

 

[Fosti]

I had that tractor for 20+ years. The only time I had no start problems was with a weak battery. I suspect that you have a battery drain issue somewhere.

 

[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.