Newbie desperately needs help with 675b

[TT67]

I have a 675b 1991 model,it has been a good unit for years but of course now when I need to finish grading my patio,it is acting up! The skid will start,then run maybe 10 seconds,maybe 30 seconds,sometimes longer-then die. As soon as it dies,it will start right up again,and do the same thing. After it does it 3-5 times,it will stay running for hours with no probs. If I remove the return spring for the fuel shut off arm,it will start and never die-this made me think it was the solenoid getting weak. I replaced the trombetta fuel solenoid-but it didn't help. I now realize that the solenoid is still being de-energized,but with the spring unhooked the solenoid can't pop out,so it stays running. Any ideas on what may be making the solenoid de-energize? I appreciate any help you can give. Thanks.

 

[Tazza]

It sounds like a bad connection somewhere... If you say it normally keeps running it doesn't sound like a protection device shutting the engine down. Check your grounds near the solenoid, then check the connectors.
At least it gives you a starting point.

 

[skidsteer.ca]

It sounds like a bad connection somewhere... If you say it normally keeps running it doesn't sound like a protection device shutting the engine down. Check your grounds near the solenoid, then check the connectors.
At least it gives you a starting point.

No sure on that machine, but often these solinoids are powered through a "spdt relay" which does the switching of the heavy current load. Go to your local auto parts store and ask for one if you are not sure what they are.$10.00
Then search the machine for one or more. Hopefully there function is labeled if there are several.
Bobcat uses these for glow plugs, park brake, switched power and the fuel solinoid. Hopefully they are labeled and on or near the fuse panel but the could be anywhere on the wire harness.
If defective they can cause power interuptions with the results you mention.
Ken

 

[mllud]

No sure on that machine, but often these solinoids are powered through a "spdt relay" which does the switching of the heavy current load. Go to your local auto parts store and ask for one if you are not sure what they are.$10.00
Then search the machine for one or more. Hopefully there function is labeled if there are several.
Bobcat uses these for glow plugs, park brake, switched power and the fuel solinoid. Hopefully they are labeled and on or near the fuse panel but the could be anywhere on the wire harness.
If defective they can cause power interuptions with the results you mention.
Ken

You have a lot going on there. I would just like to remind you. A lot of safety interlock systems are made to let it run for 30 sec/ and shut it down. They do that so you can move it to a good place to repair/load
If you remove a spring and overide your safety shutdown it could be bad.I would make sure all is good with pressures and temperature.
Sounds more like what ken was saying. Mike

 

[TT67]

You have a lot going on there. I would just like to remind you. A lot of safety interlock systems are made to let it run for 30 sec/ and shut it down. They do that so you can move it to a good place to repair/load
If you remove a spring and overide your safety shutdown it could be bad.I would make sure all is good with pressures and temperature.
Sounds more like what ken was saying. Mike

thanks for responces. the fuel shut off solenoid is opened by the starter solenoid energizing,then held open by a different circuit. a slight blink in the supply power is all that is needed to make it release,and it won't pull in again until you hit the starter. it turns out it was simply a poor connection on the main chassis ground terminal-the bad ground would wink the 12v for a nano second, which was enough to let the solenoid pull out. hopefully this may help someone else. thanks.