tractor cranks but fails to start or dies shortly after

[Lots o work]

Hi all!

I have L4330 HST. trying to diagnose an issue.

engine will crank. sometimes will not start. sometimes will start and then die shortly.

I do not think it is HST switch or clutch switch because it will crank. I do not think it is pto switches for same reason.

Sitting squarely and still on seat, If it starts it runs smoothly and will just die shortly like a kill switch was pushed. I think its possible the seat switch is out of adjustment or going bad. the seat switch is 3 wire, with a multimeter, it appears to activate each of 2 posts in slighly different positions. with the switch completely up: its one configuration, midway down the middle pin changes resitance, farther down the 3rd pin changes resistance. I cant figure out what purpose this serves. So Im not sure which posts I could jump across to bypass the seat switch for testing purposes.

I was told the seat switch kills the engine by cutting power to the fuel solenoid. on this tractor i don't know what else is in the circuit to test. is there a way to test if the fuel solenoid is getting power, or if it is bad?

last winter in very cold weather it would not even crank, occaisionally if I fiddled with the HST foot pedal I could get it to crank. When the weather warmed up, it ceased to be an issue. I thought it might have been an ice issue. Today I finally located the switch and adjusted it in a bit so the plunger would engage a little more when the pedal was in neutral. I forgot to take the key today to the location where the tractor is, so I couldn't experiment. I theorized the seat switch may be bad or slightly out of adjustment and the HST switch also. I could tape the seat switch fully down temporarily and see if it stays running.

I don't know if Im on the right track or its something completely different. any help is appreciated!

 

[Russell King]

Yes tape it down and see if that will keep it running.

The different position of the switch may be to allow the rear pto and tractor to operate with the seat forward (tilted up). If you have the operator’s manual research that operation for a log splitter or similar implement that requires rear PTO and operator out of the seat. There may be some magic in time or sequence of operation to allow the operation

 

[Lots o work]

I fiddled with the "key stop" fuse near the battery under the hood. I could hear the fuel stop solenoid clicking with the key on when I did it. I pulled inspected and reseated the fuse. and it started and I used the tractor for an hour, then the same thing happened. A multimeter showed no voltage part of the time at the fuel stop solenoid. so I guess we're still trying to diagnose.

Anyone know where to get a free wiring diagram for this tractor?

 

[MOOTS]

I fiddled with the "key stop" fuse near the battery under the hood. I could hear the fuel stop solenoid clicking with the key on when I did it. I pulled inspected and reseated the fuse. and it started and I used the tractor for an hour, then the same thing happened. A multimeter showed no voltage part of the time at the fuel stop solenoid. so I guess we're still trying to diagnose.

Anyone know where to get a free wiring diagram for this tractor?

Define “fiddled with fuse”. I’ve had fuses look good and even test good. Wiggle the tabs a bit, and it will test bad. I’d pop a new fuse in and go from there.

 

[GeoHorn]

Take a new fuse-holder with the proper sized fuse in it…and create a “jumper” …. to jump-across the existing fuse. If this solves the problem then the likely culprit is the old fuse or its’ holder.

If it doesn’t solve the problem…the next thing to consider is fuel starvation…? (clogged filter, clogged tank vent, failed/intermittent fuel solenoid)

 

[Lots o work]

Hi all!

I have L4330 HST. trying to diagnose an issue.

engine will crank. sometimes will not start. sometimes will start and then die shortly.

I do not think it is HST switch or clutch switch because it will crank. I do not think it is pto switches for same reason.

Sitting squarely and still on seat, If it starts it runs smoothly and will just die shortly like a kill switch was pushed. I think its possible the seat switch is out of adjustment or going bad. the seat switch is 3 wire, with a multimeter, it appears to activate each of 2 posts in slighly different positions. with the switch completely up: its one configuration, midway down the middle pin changes resitance, farther down the 3rd pin changes resistance. I cant figure out what purpose this serves. So Im not sure which posts I could jump across to bypass the seat switch for testing purposes.

I was told the seat switch kills the engine by cutting power to the fuel solenoid. on this tractor i don't know what else is in the circuit to test. is there a way to test if the fuel solenoid is getting power, or if it is bad?

last winter in very cold weather it would not even crank, occaisionally if I fiddled with the HST foot pedal I could get it to crank. When the weather warmed up, it ceased to be an issue. I thought it might have been an ice issue. Today I finally located the switch and adjusted it in a bit so the plunger would engage a little more when the pedal was in neutral. I forgot to take the key today to the location where the tractor is, so I couldn't experiment. I theorized the seat switch may be bad or slightly out of adjustment and the HST switch also. I could tape the seat switch fully down temporarily and see if it stays running.

I don't know if Im on the right track or its something completely different. any help is appreciated!

Update:

we traced the problem with a test light to the "timer" module in the OPC circuit (located behind the dash). bypassed it and haven't had an issue since. Ive got a new one ordered.

the timer creates a 1 second delay in the OPC circuit when an OPC combination of switches opens the circuit. this is helpful when the seat switch momentarily opens then closes (such as on bumpy ground) I theorize that it also protects the solenoid from excessive off/on operation and prolongs the life of it?

Russel you are correct on the three positions of the seat switch. Thanks!

Matt, good suggestion. we inadvertently blew that fuse when we were experimenting, so a new one went in, but that didn't solve our problem in this case.

This kind of issue makes it tempting to bypass the entire circuit, but I think the extra measure of safety is well worth it. I've had enough weird things happen to appreciate the need for it.

Thanks every one for the help!

 

[Mark_BX25D]

This kind of issue makes it tempting to bypass the entire circuit, but I think the extra measure of safety is well worth it. I've had enough weird things happen to appreciate the need for it.

You are wise, grasshopper.

Nice troubleshooting, too!

 

[GeoHorn]

My M4700DT (gear drive) has only one safety switch… the Range Lever must be in neutral for the start. I had an intermittent start issue that provoked me to bypass the safety switch and operated like that for awhile.
Then it occurred to me that in the next few years my kids kids will likely be operating this tractor.
I did some more trouble-shooting and discovered the safety switch activated an additional start-solenoid that controls power to the starter piggy-back solenoid. That addt’l solenoid was the actual culprit in the intermittent starts….. so thinking about my grandkids safety when they’re old enough to operate their Gone-West Pop-Pops tractor…. I replaced the intermittent safety-solenoid and re-instated the Range Lever safety switch.

(I also keep detailed maintenance records in dedicated spiral notebooks on all my equipment. It gives me pleasure to imagine them someday reading the detailed maintenance and troubleshooting I perform. Of course, that pre-supposes they will be able to read the ancient art of “long hand” (cursive) hand-writing. Kids these days view it in the same light as Japanese Kanjii or Chinese Calligraphy.)