3910 Pull starting works, but not with the key?...

[BondoBuilder]

I recently purchased a 1986 Ford 3910 to do some minor chores on the farm like feed hay, spread manure, rake hay, and mow pastures. The starter/battery was really weak when I got it. I tested the alternator and it was dead.

Because money is tight, I did not replace the alternator right away. For the past 5 months, I have either pull started the tractor or left it on a hill and roll started it.

I finally had enough cash to go through the whole tractor. I fixed all of the leaks, changed all of the fluids, put on a new coat of paint and a new set of decals, and rewired the whole thing.

My wiring job included a new battery (Interstate Brand), voltage regulator, rebuilding the starter, and alternator.

Yesterday, after getting the wiring complete, I started it up. It fired right up!! I was pumped!

Within an hour, my father went to start it, and it just cranked, and cranked, and cranked. It was 58 degrees here in Kentucky. I thought maybe it was too cold, so I plugged in my freeze plug block heater for a few hours. Still nothing, just cranking... I had to feed some hay, so I went ahead and pull started it. It started within 5 feet of being pulled.

What could be the problem? I have never, ever used ether on it, but could this be an "ether addiction" caused by the previous owner?

Or, worse, could the compression be bad?

Thanks in advance!

 

[JC-jetro]

Do you have fuel shut off solenoid? is the fuel shut off open with not key in?

JC,

 

[BondoBuilder]

It has a mechanical injection pump, and fuel is gravity fed from the tank, through the filter, to the pump.

The injection pump is shut off via a cable linked to the injection pump.

Where would the solenoid be?

Yes, fuel is on. And tge fuel filter was replaced.

 

[sweep]

Since you repainted the tractor could you have excess paint buildup under the negative battery cable?

 

[JC-jetro]

With your description you do not have solenoid fuel shot off valve. it is a normally closed shut off valve (no voltage=closed), once switch is in the ignition and turned on then the solenoid opens and allows fuel to go to the injectors. The mechanical linkage to the injector pump does that in a manual mode. Is it in open position when engine fails to start?

JC,

 

[jinman]

It seems that you are not reaching the "critical rpm" with your starter. If it started fine right after replacing everything and now needs a roll-off start, it is probably because the starter is turning a few rpm too slowly. I would think you could check the electrical system by charging the battery using an external charger. Measure the exact voltage on the battery before attempting a start, and then see if the engine will start. If the engine starts, leave the tractor for a few hours and then check the battery voltage again. If the voltage is a bit low (less than 12.6 vdc) It may indicate that your have a small leakage in the electrical system that could pull the battery down. Is the new battery you used one with the recommended cold cranking amps (CCA)?

I just think the fact that the tractor started once and then won't start a few hours later is an indication that there is something going on to cause a few less rpm at the starter motor. It is likely not mechanical binding, but rather could be battery voltage drop or improper CCA. Just a guess. . . .

 

[Jerry/MT]

I recently purchased a 1986 Ford 3910 to do some minor chores on the farm like feed hay, spread manure, rake hay, and mow pastures. The starter/battery was really weak when I got it. I tested the alternator and it was dead.

Because money is tight, I did not replace the alternator right away. For the past 5 months, I have either pull started the tractor or left it on a hill and roll started it.

I finally had enough cash to go through the whole tractor. I fixed all of the leaks, changed all of the fluids, put on a new coat of paint and a new set of decals, and rewired the whole thing.

My wiring job included a new battery (Interstate Brand), voltage regulator, rebuilding the starter, and alternator.

Yesterday, after getting the wiring complete, I started it up. It fired right up!! I was pumped!

Within an hour, my father went to start it, and it just cranked, and cranked, and cranked. It was 58 degrees here in Kentucky. I thought maybe it was too cold, so I plugged in my freeze plug block heater for a few hours. Still nothing, just cranking... I had to feed some hay, so I went ahead and pull started it. It started within 5 feet of being pulled.

What could be the problem? I have never, ever used ether on it, but could this be an "ether addiction" caused by the previous owner?

Or, worse, could the compression be bad?

Thanks in advance!

To start a diesel is reasonable mechanical condition, you need adequate fuel and air to the engine and the starter must be able to crank the engine over at something like 200-300 rpm during the start cycle.

Check the air filter to make sure it's not clogged.

Since you can easily pull start it, it would seem to me the rebuilt starter performance may not be up to snuff. if the starter has been properly rebuilt, then the power supply to the starter would be suspect.
What oil are you using in the crankcase? At 58F, 15w40 should be OK and with the block heater on for 2 hrs, your starter should really spin the engine over. Did you replace the battery cables? Make sure that your starter cables are not corroded internally. They can look good on the outside yet have internal corrosion near the battery end lugs. Look for cracks on the cable lugs that don't allow tight contact with the battery terminals.Check the ground for the starter and the ground for the battery negative battery cable.

 

[BondoBuilder]

Update guys!

I plugged the tractor in when I first woke up (6am), New Year's Day. At that time it was about 45 degrees.

I finished my feeding by 930am, grabbed a bowl of cereal, and hopped on the tractor. It fired right up! I let it idle for about 15 minutes at 1000 rpms.

I turned it on and off all day long while spreading manure, and it was fine. It was near 60, at 1pm yesterday.

I think it was just too cold. I also do believe the previous owner used ether on the tractor...

Thanks for your help!

 

[BondoBuilder]

Some pics, before and after:

Thanks again guys!

 

[jinman]

You sure made it look purrrrdy.:thumbsup: Let's hope that you don't have to tear back into it. I know you don't want to do that after all your careful work you've done.