Cat 303.5 CCR Throttle Issue

[Guns N Rotors]

My 2006 303.5 is acting up. With the auto idle on, the machine keeps
revving up and down while I'm digging.

With the auto idle off, she'll dig for two minutes then idle down.
I have to shut the machine off and restart it to hold throttle
position.

Also, the throttle will stay at low idle as I rotate the knob through
half speed, half throttle at the full speed mark and full speed when
I rotate the knob way past the full speed position.

Has anyone had similar experiences with Cat excavators?

Any help would be greatly appreciated.

Thanks, GnR

 

[stumpjumper83]

Is it popping error codes? Can you pull the throttle controll and see if its a variable resistor and not functioning correctly?

 

[NEEM PTY LTD]

Yeah the first thing you will need to do is throw a lap top on n check for active code....
I know they did have a few problems with the 268-0761 throttle position switch with moisture getting in and shorting, Cat say they have improved this switch but we still have an occasional problem with then now and then.

Maybe fuel? I would just check to be sure, plugged filters, kinked line creating a restriction not allowing the engine to run at high idle for long. I've seen weirder things

 

[Red Bank]

We had a similiar issue with our Cat 303.5, one day it would not idle down, stayed wide open, cut it off and brought it back to the yard and then it would not idle up. I replaced the throttle control switch and it fixed it! It was pretty easy to replace.

 

[caterpillar72]

i remember that happened to a cat excavator i was working on the throttle wouldn't rev up or down and the machine kept dieing had a guy from the cat dealer come by and told us the computer was turned off so the throttle cancels out

 

[Per Eriksson]

No computer on this model, change the throttle control and it'll be fine, common problem.