JD 110 Starting Issues

[frencht]

I started my 2003 JD110 (S/N 100063 with 2332 hours) several times over the winter with no problems. I recently started it and left it to warm up at idle while I gathered up my engine oil changing gear. When I returned, the machine had quit and would only run for a couple of seconds before it died. A quick check of fuel level, fuel filters, bled the fuel lines etc. and all checked out fine except the electric fuel pump didn't seem to be working when I turned on the key. I checked the voltage to the fuel pump and and found that the electric fuel pump wasn't getting voltage with the key on or when the engine briefly started. I checked the service manual and found there is no mention of the electric fuel pump in the theory, troubleshooting check points nor in the wiring diagrams. I then disconnected the fuel pump, created and connected a couple test leads to the pump and an extra 12 volt battery. Alas, the fuel pump vibrated but made no apparent difference to the engine starting and then stopping within a couple of seconds.

I hopped on the web, searched and found a couple of hits relating to a 3 second timer and one suggesting that the 3 second timer function implementation varied; some machines used a sensor to trigger the timer and others used a signal from the alternator to trigger the timer. I immediately checked my alternator and found the belt adjustment was at the limit and there seemed to be a bit of slack in the alternator belt. I made a trip to my local John Deere dealer bought a new LVU11661 alternator belt (40 amp alternator). Wanting to avoid the warnings in the tech manual about removing and reinstalling the hydraulic pump without the special alignment tools, I spent a few hours disassembling the anti-vibration coupler from the crank shaft, changing the belt and finally reassembling the anti-vibration coupler. I started the tractor and it died within a couple of seconds. I tried a few more times with no luck, however, as I pivoted to watch the console while I attempted to start the tractor, my foot lightly depressed the forward pedal and when I turned the key the yellow book icon flashed but the tractor kept running. I was able to drive it around and all functions appeared to work fine....no problems. The tractor idled just fine for several minutes before I shut it off. I then proceeded to start the tractor and stop it several times with no problems.

Thinking that I must have cleared an error or something by driving the tractor around, I decided to change the oil as originally planned. Upon completing the oil and filter change, I stared the engine again but it only ran for a couple of seconds before it shutoff. I then tried starting it again with my foot gently pressing the forward pedal and I noticed the yellow book icon flash briefly and the engine continued to run and everything again seemed fine.

So I'm left with two issues:

1) An electric fuel pump that isn't getting voltage and no wiring diagram to understand where the voltage is supplied to the pump.
2) A starting issue that seems to be bypassed initially by starting the engine with the forward foot pedal slightly depressed. Any attempts to start with little time elapsed between previous successful starts and stops also seem to work fine.

Anyone with any insight?

Thanks in advance,
Tim

 

[MH110]

Do you have the service manual? A member on here emailed me a copy a year ago but I don’t have their information. There is also a solenoid that is a part of the starting sequence that could be contributing to this issue. This could so be a relay issue too.

 

[frencht]

Do you have the service manual? A member on here emailed me a copy a year ago but I don稚 have their information. There is also a solenoid that is a part of the starting sequence that could be contributing to this issue. This could so be a relay issue too.

Yes, I have SM1987 JUN02, which admittedly is a year older than my 2003 JD 110TLB. I have pulled and reseated relays 1-4 but no change. I do hear the fuel shutdown solenoid click prior to each attempt to start. I've reviewed the wiring diagram for the 3 second timer and assuming the service manual didn't change the 3 second timer wiring for 2003, the 3 second timer should remain reset as the seat switches are bypassed. I did have the seat pan off last summer to replace the gear selector level pin in the top of the transmission, so I'll be looking into the parking brake switch wiring. If I pull the PTO switch up before trying to start, the starter never kicks in, therefore, unless the PTO switch contacts are bad when the PTO switch is in the OFF (down) position, the switch appears to work. The backhoe has never been off the machine and I don't think I have ever pulled up on the PTO switch to turn it ON before, I wouldn't think there is an issue with the switch unless there is a loose connection, something else I will need to confirm when I have a chance to pull the fender closure apart.

Thanks for your reply,
Tim

 

[MH110]

Yes, I have SM1987 JUN02, which admittedly is a year older than my 2003 JD 110TLB. I have pulled and reseated relays 1-4 but no change. I do hear the fuel shutdown solenoid click prior to each attempt to start. I've reviewed the wiring diagram for the 3 second timer and assuming the service manual didn't change the 3 second timer wiring for 2003, the 3 second timer should remain reset as the seat switches are bypassed. I did have the seat pan off last summer to replace the gear selector level pin in the top of the transmission, so I'll be looking into the parking brake switch wiring. If I pull the PTO switch up before trying to start, the starter never kicks in, therefore, unless the PTO switch contacts are bad when the PTO switch is in the OFF (down) position, the switch appears to work. The backhoe has never been off the machine and I don't think I have ever pulled up on the PTO switch to turn it ON before, I wouldn't think there is an issue with the switch unless there is a loose connection, something else I will need to confirm when I have a chance to pull the fender closure apart.

Thanks for your reply,
Tim

This may sound stupid, but swap your brake light relay with one of the relays that are involved in the starting sequence and see if anything changes. I took each relay out from the main and aux harnesses and tested each one both ways and half were bad. I ended up replacing the entire wiring harness for the whole tractor and that solved a lot of my issues. I also had to clean the main grounds and bypass the pressure sensors for the seat, which may also affect your ability to start or move the tractor.

 

[radios1]

sounds like a defective switch on the forward pedal. the way it's supposed to work is it's supposed to prevent starting if pressure is applied to the pedal, so the tractor don't move when starting!..