Cat 312 auto idle inop

[digger_hunter]

Hi all,
I have a problem similar to another post i've seen on this forum. Basically the exhaust got busted on a Cat 312 and melted the inner sleeve off the stepper motor cables.

Its a used digger and it looks like the guy who had it previously just connected a extra cable to the throttle and just ran it like that.

But I put new cables and the put everything back the way it was meant to! So now all works ok including engine revs using the engine speed control. But the only issue is that the digger will not auto idle after 3 seconds as it says on the operator manual.

Any advice from the seniors n how i can trouble shoot this? Is there anything in particular i should look at like wiring from a sensor etc.?

Thanks

[CRAFT]

I guess you've checked for the obvious things like the short rod with the ball sockets on each end, from the solenoid to the throttle linkage that it is not binding or is still hooked up (those ball sockets have been known to seize-up or wear to a point of falling apart) ...... from there I would check to see if the 2 wires are still conected to the back of the solenoid ..... I would try and run a 24v jumper to the solenoid and see if it shifts when energized (plunger pulls in when powered up) ........ if all those things check out you'll probably start going deeper in things like the fuse power to the relay switch, checking to see if the auto-idle button in the console is working ....... these would be just basic things to check and test first ...... good-luck


OBTW : when you installed those new cables ..... did you run the machine thru the self calibration mode ...... you'll need the cheat sheet from Cat how to do that ...... its done thru the pressing a sequence of the buttons in the console including the secret button that is an unmarked indent but not identified as a button
Some times the cables go out of sinc and comp has to go thru the self calibration mode to get the cables stroking properly .... hope this may help you a bit .... cheers

[Boiled Owl]

When my 320B auto idle wouldn't work, it was the sensor on the flywheel gone bad.

[digger_hunter]

Hi CRAFT,

Do you have the instructions for recalibrating the stepper? Also does anyone know if the control units for 311, 312 and 320 re interchangeable? Our 311 computer just went dead! and all i can find is a used 320 controller. So any help appreciated fellas.

[kbeen]

hello, you do have the auto idle feature turned on at the monitor i guess ?