Starting Issues

[coryip]

I wanted to post here since the Bobcat is so similar to many Kiotis and theres more activity in here.
Hello and hopefully someone can give some advice to get this thing running again.
A few weeks ago the tractor started showing signs of something wrong. It turned over but would not start but the problem was intermittent and only happened 3 times over a 2 week period. Now it never starts regardless of how many attempts. I have replaced the relay and swapped the 2 under the hood just to double check. I have checked all connections under left floor board sprayed with contact cleaner and greased. It seems that all safety switches are doing what they should because the tractor turns over. I pulled the fuel solenoid and with ignition on the plunger will hold I can reinstall and tractor will start. I thought a possible bad solenoid so tried a new one but no luck. I have also tested the connection to solenoid and get the 1 second 11-12V when turning to ON position and the other terminal shows 11-12v constant. Is it possible I have 2 bad solenoids because it seems the tractor is doing what its supposed to do but just not engaging the solenoid. Is there a way to test the solenoid or does anyone have another suggestion.
Thanks

 

[ritcheyvs]

You should be able to hear if the stop solenoid is working. When you turn the key switch ON (but not to crank or glow) you should be able to hear the "thunk" as the plunger retracts. Likewise, you should be able to hear the "clack" when it extends (engine not running) as you turn the key to OFF. Just for grins, squirt some WD40 or electrical contact cleaner into the keyhole and cycle the switch several times. Wonky key switches are very common and this lube process sometimes does the trick. The switch isn't hard to replace and can even be disassembled and cleaned if you are careful. If WD40 doesn't help make sure you have good fuel delivery to the injection pump. Disconnect the fuel line and verify good gravity feed to the lift pump. Verify good flow out of the filter; I think you have a manual pump lever on the lift pump for this so you don;t have to actually crank the engine. Air leaks INTO the fuel line will also cause problems.
Check the voltage at the glow plugs to ensure they get power during the glow cycle. If all that checks out, pull the "oil fill" plate below the injection pump and make sure the rack isn't jammed. See the sticky post at the top of this forum if you suspect IP problems. The IP gear failure problem seems to be limited to 2005-2008 models.

I should also add that you need a healthy battery to start a Diesel. That motor needs to spin pretty fast and glow plugs need to be hot for compression ignition to work.

 

[coryip]

I have cleaned the switch with electrical contact cleaner with no luck, I didn't try wd40 though. Wouldn't fuel delivery, glow issues, injection pump be eliminated if I can turn key on, remove solenoid, push in plunger and it holds, reinstall, then turn key to crank position. When doing this it fires right up and runs as it should. Battery is fairly new but i did remove terminals and clean though they looked good already. Its the initial pull of the solenoid thats not happening, when shutting down it releases fine.

 

[ritcheyvs]

Before going further, I need to confirm that you have the second version on the non-tier 4 engine with the stop solenoid on the front of the engine (vs externally on the right side). All of the following is based on that configuration.

If I understand correctly:

1. Cleaning the switch made no difference.

2. If you unbolt the stop solenoid (SS) turn the key ON, push the plunger in with your finger (it stays in) and reinstall the SS, then the engine starts and runs normally. Is that correct? If so, then yes, the switch, glow, and fuel feed should be OK. But the SS plunger should retract all by itself when you turn the key to ON (you should not need to push with your finger) so if the SS plunger did not retract without help, that is the problem.

I am still somewhat confused because the SS ground (for pull and hold coils) is through the engine block. The SS plunger should not have stayed retracted unless you somehow provided a continuous ground connection (like a jumper wire) while you tested and reinstalled the SS.

I guess you didn't try (or couldn't hear) the SS plunger retract when the key is turned ON. Or maybe you just didn't comment.

If the SS is grounded to the engine block the PULL coil should be energized briefly when the key is turned to ON, causing the plunger to retract (and stay retracted via the hold coil which is powered until the key is turned OFF). The engine cannot start or run unless the SS plunger is retracted. If the SS plunger does not retract on its own when the key is turned ON (vs pushing it with your finger) then either the SS PULL coil is bad (not common) or the SS relay (on firewall) is bad (most common) , or the Display Unit (which provides the 1-sec ground to the relay) is bad (not common).

By the way, the SS relay is a common automotive relay available at any car parts place (like AutoZone, Oreilly's, etc.). The SS pull coil current is close to the 30 amp contact rating of the stock relay so it's good to upgrade to a 40 amp relay if you replace it. I seem to recall reports where a marginal SS relay worked OK for the starter but not for the SS

 

[countrybumpkin]

To add to the above info, you said you are getting the 1-2 second power supply on the retract wire, I'm wondering if it's a bad connection or wire not allowing for full amps to pull the coil in. It may show 12 volt on a meter with out a load but when you add the coil load it can't pull enough.

 

[coryip]

Yes SS is on the front right side of engine held on by 2 10mm nuts. Mine has the 3 terminal connection, to my knowledge ground is center terminal then pull 12V on one side constant 12V other.
1 Cleaning switch made no difference
2 You are correct its the Pull of the SS thats not happening all of the sudden
I can hold the SS in my hand with key on and plunger will stay in. Yes its definitely not getting pulled in when turning the key because its an obvious sound.
I have replaced the relay with a kioti replacement and also swapped with the other one under the hood with no success. I have purchased a new kioti SS but it acts the same way. i have metered the terminals and get the 1 sec to pull.
To country bumpkin is there a way I can test if the amperage is there.
Thanks

 

[countrybumpkin]

You should be able to put the probe from the multimeter on the connector for the pull circuit while it's still connected to the SS, then turn on the key (may need a second set of hands) then see if it reads 12 volts the entire couple of seconds it has power. If it drops then I would suspect a bad connection or bad spot in a wire someplace. You could also run a jumper wire straight from the battery positive post to the SS post that pulls the plunger in and see if it activates it, just don't hold that on more than a few seconds.

 

[ritcheyvs]

A couple thoughts:

The start and SS relays are the same but there is no guarantee which is which. So insure you have correctly identified the SS relay by pulling the connector off (what you think is) the start relay and confirming the starter won't turn with that relay disconnected.

There is also a glow relay but it's different (higher current rating), so don't confuse it for the SS relay.

I would try both of the tests bumpkin recommends (pull voltage at SS under load and 12v direct to the pull terminal of the SS).

Your Bobcat may be different but I think my Kioti SS has three terminals (one is ground) but there are only two wires in the connecting harness.

You can see if the SS relay is functioning by feeling vibration when turning the key to ON. This would be best using the (now) spare relay to isolate it from any vibration from the adjacent glow relay. If you can feel movement in that relay then the Display Unit is probably OK but the relay contacts can still be bad.

There is a suppressing diode (back biased) across the pull coil to minimize arcing at the SS relay contacts which could cause problems if it's bad. If the diode is open circuit that would cause rapid pitting of the relay contacts. If it's failed as a short it would shunt current around the pull coil and maybe blow the 25 amp fuse.

If I had to guess at this point, I'd guess bad (burned) contacts in the SS relay.

 

[coryip]

Thanks for the input so far. I should get a chance over the next couple of days to troubleshoot.

 

[coryip]

From left to right when looking at firewall
Relay 1 70 amp Unplug and I have no glow
Relay 2 30 amp. Unplug and I get no change
Relay 3 70 amp. Unplug and I get no starter.
I had replaced and been swapping the 3rd relay because I thought that was the stop relay. It was the middle relay.
Went to local NAPA and picked one up and that solved the problem.