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Mustang / Gehl Intermittent Start Once Warm

customfab

Member
Joined
Dec 10, 2015
Messages
14
Location
Texas
I have a low hour Mustang 2105 with the 110HP Yanmar engine. Same as the Gehl 7800. Has only 1200 hours.

It is a great machine but since I've purchased it used, it has very annoying intermittent starting issues. I'm not sure if it is electronic or not.

Basically the machine always starts when I fire it up at the beginning of the work day or anytime that machine has been sitting for hours.

Seems once it get warms that it will periodically not start. And the symptoms are very strange. Seems to occur more if I accidentally stall out the machine when aggressively loading the bucket.

So once we've operated it for a bit and then shut it off or occasionally stall it, it sometimes won't start. Basically, if you move the key to the ignition ON position (wait a few seconds) and them move the key to the crank position, about 50% of the time it will not start. It will just crank and crank and crank. Won't even try to fire up whatsoever. However, if I move the key quickly from the OFF position and turn it immediately to the crank position (past ignition ON), it will fire up & then immediately stall out OR stay running. If it stalls immediately, then I simply repeat. Turn the key OFF and then quickly to the crank position. Usually if I repeat this 4-6 times, it will fire up & stay running. Very strange!!

90% of the time I can do this and it will eventually stay running. Then the machine runs great. So once the machine is warm, I typically avoid shutting it down. And I feel the symptoms occur more often if I accidentally stall out the machine.

Occasionally, this trick will not work. So I simply leave the machine to sit for a few hours. Then I jump back into it & it will start fine. I can turn it to the ignition ON position and then crank it right up.

Any ideas what to look for?
 

Vetech63

Senior Member
Joined
Aug 10, 2016
Messages
6,362
Location
Oklahoma
So am I understanding that the engine actually cranks 100% of the time, but doesn’t start some of the time?
 

thepumpguysc

Senior Member
Joined
Mar 18, 2010
Messages
7,445
Location
Sunny South Carolina
Occupation
Master Inj.Pump rebuilder
Shut off solenoid at the rear of the inj. pump not getting full power to PULL the sol. in to the run position..
It sounds as if u have a key switch problem, if u can rapidly turn the key & it'll start..
The sol. gets its PULL IN power from the starter.. check to make sure ALL the connections are CLEAN & BRITE & TIGHT..
EVERY skidsteer I'v worked on, the cab is completely full of dirt.. so pull that key switch out & have a look 1st..
 

customfab

Member
Joined
Dec 10, 2015
Messages
14
Location
Texas
Thanks, for that input pumpguy. I'm doubtful it is the key switch but it could be for sure. I say this as if I rapidly turn the switch is will start but only after I rinse & repeat the quick turning 6-10 times in a row. That works 90% of the time. But 10% of the time, it simply will not start until the machine is left for a few hours.

Seems more likely the shut off solenoid that you described is going out? Maybe it heats up and doesn't function reliably? Thoughts on that? I'll have to dig to access it and can share some pics to make sure I identify it correctly.

And yes, Vetech63, the motor runs great. It is all about erratic starting once the machine is warmed up. NEVER occurs when the unit is cold. It starts up from Cold 100% of the time. Reason why I don't believe it is the ignition switch.

Thanks for the input!!!
 

Delmer

Senior Member
Joined
Jan 3, 2013
Messages
8,864
Location
WI
Yes, it sounds like a relay to me. There's gonna be lots of garbage to sort through on the wiring, do you have a diagram? Relay's are easy enough to change out and see if it works. otherwise, start at the injection pump, see what gets power cold and doesn't get power hot, then you know where to go next. Have you actually looked at the injection pump? might be something obvious there, whether cold, or not pulling in hot like thepumpguy says.

Don't know this is external or internal, look.
 

Phelton

New Member
Joined
Jul 15, 2023
Messages
1
Location
Georgia
I have the same machine and had the same problem. Tried everything for over a year..finally found it ! Replaced hot cable from battery to starter that was the fix! There was a tight spot where the frame rubbed the cable bare. Never had the problem again and I run it almost every day
 
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