Deuce RPM Idling too Fast

[appalachiantraildeuce]

My M35a2C is idling a little fast at around 1500 to 1700 RPMs. Any suggestions for a diagnosis and quick fix? I tried a number of different search words to find an existing answer with no luck. Many thanks my friends!

 

[Wildchild467]

Check to make sure your throttle linkage is not obstructed and moves freely. Maybe something is worn with the linkage not allowing it to move all the way back up. 1500-1700rpms seems really high....high enough where it would be too fast for the idle speed on the injection pump. also try moving the arm on the injection pump towards idle and see what happens then. or maybe its a broken or weak throttle return spring. My dad had one break on his truck once.

 

[drgreg]

Could it be a flame heater leak?

 

[deuceman08]

i had that problem but and i could adjust it down but it was only at 1200rpm.

 

[paradeduty]

Stupid question - but here it goes ....... is the hand throttle all the way back in toward the dash? Someone may have pulled it out by mistake.

 

[appalachiantraildeuce]

Thanks all. Hand throttle was the first thing I checked. I might have been to embarassed to admit if that was the issue. I'll let you know what I find from the other suggestions. Saturday is my day to play with my truck and its supposed to be sunny. Can't wait!

 

[wsucougarx]

Throttle pedal return spring?

 

[airmech3839]

I have had issues with the cutoff handle rod on the IP has gotten bent/corroded..might have similar issue with throttle rod and or spring! just my

 

[Warthog]

My M35a2C is idling a little fast at around 1500 to 1700 RPMs. Any suggestions for a diagnosis and quick fix? I tried a number of different search words to find an existing answer with no luck. Many thanks my friends!

To help diagnose the issue:

Has the truck always done this? Just started? Any changes made to the truck?
Worked on the IP lately?

We need more info.

 

[appalachiantraildeuce]

I haven't had the truck long, but has always idled a little fast.

Every once in a while when I rev up the engine a couple of times at a stop light it will slow down to around 10,000 RPMs. That makes me think something is sticking and gets loose when I rev the engine.

I changed the fan belts and afterwards, the first time I cranked it up, it was no longer idling fast, but then returned to the way it had been after driving a few minutes. I have no idea what effect that would have had.

 

[appalachiantraildeuce]

This may be a bad newbie question, but what is an IP?

 

[Boatcarpenter]

That would be your Injection Pump.
BC

 

[wb1895]

Is it a constant fast idle or is it surging?? When I changed out fuel filters on my deuce I got some air in the fuel lines and for about a week my deuce would surge from about 1000 RPM to 400 RPM.... Just a thought.

 

[Warthog]

I
Every once in a while when I rev up the engine a couple of times at a stop light it will slow down to around 10,000 RPMs....

WOW, you must have the NASCAR Deuce...........Just messing with you.....LOL



With the infomation you provided about the truck, lets try a couple of items.

With the fast idle, I would check the Fuel Control Rod - FCR. It may be sticking.

Checkout these links and look for info on the FCR:

http://www.steelsoldiers.com/deuce/29359-m35a2c-clogged-fuel-system.html

http://www.steelsoldiers.com/deuce/49153-help-hydraulic-head-removal-gone-wrong.html

The Fuel Control Rod controls the amount of fuel that is sent into the Injector Pump - IP. It is behind the fuel Shutoff cover on the side of the pump.

The Rod controls the Plunger Sleeve, which inturn controls the amount of fuel that the Hydraulic Head - HH, uses and also in the stop position opens the Spill passage to stop the fuel flow.

So first, remove the Shutoff cover and see how the rod moves. Easy or Hard.

If hard, you will need to remove it and clean it and the passages with carb cleaner. MAKE SURE you do not loose the small pin at the tip of the rod.

Let us know what you find.

Warthog