MC-12 Throttle Problem, travelling

Beachfinn · September 06, 2016, 06:57:37 AM

All,
as usual, as we started our vacation trip yesterday an issue arises. I was coming down hill and as i started to throttle up for the next hill i noticed that the bus did not respond to throttle. pulled aside and had no throttle responce, but bus idled just fine. Shut her down and checked the usual stuff, all seemed ok. pulled the connector on the throttle potentiometer, as I figured that might have been the issue. Started her up again and got first a limited throttle function and then normal.
I've got a lot of miles to drive in next 10 days, any suggestion what else to check and whether the potentiometer is serviceable or should i try to source one?

Thanks !
Sami

luvrbus · September 06, 2016, 07:04:20 AM

It should flash a code the 21 with a TPS problem check and be sure you have the 5 volts at the TPS ? are the fuel filters clean

Beachfinn · September 06, 2016, 07:41:43 AM

Heading out to sand dunes NP on a Jeep. Filters are clean, replaced few months ago. I'll check the voltage later. How would i pull the code?
Thank you for a super quick reply !

Beachfinn · September 07, 2016, 02:04:30 PM

Normal operations 5 volts is there, problem occurs completely randomly and when it happens the 5 volts disappears......Sometimes when i shut the bus off and turn it back on it operates normally.
Driving on I70W through the rockies.

Beachfinn · September 08, 2016, 06:04:49 PM

Ok, so from colorado springs to moab it happened 4 times. I could pull over and have it idle for 3 minutes and it would operate normally. It Occurs mainly higher altitudes and while not pulling. At this point i am thinking its a DDEC3 / Fuel Problem that mainly occurs at altitude, any thoughts? im at camp at moab till saturday and then move over to grand canyon and will be heading back to denver early next week. Sure would be nice to have it fixed by then. Though i could just jump 5v to the TPS

Beachfinn · September 10, 2016, 05:46:35 PM

So,
From Moab to Grand Canyon it only happened once, 11 miles from the campground, after 7 hours of driving. Same deal 7k of altitude after cresting the hill, loose throttle. It also will not fast idle when this happens. This time it was while longer, I shut down main power and pulled the DDEC fuses, no help. It will not throttle even with engine override.
Any thoughts? Anyone?
ill try to see if there is an diesel mechanic in town that speaks 2 stroke DD, as there is an truck diesel shop...
Thanks

Beachfinn · September 18, 2016, 12:00:15 PM

Dropped bus off to W.W Williams, they tracked it down in few hours to air pressure switch for park brake. $4.83 in parts. Great guys, unfortunately they broke the wire coming off brake pedal pressure sensor. I was in the middle of desert, in dark when I noticed I had no brake lights...

Back in CO Springs after 2k miles with the bus, twice over the Rockies