Throttle adjustment?

[cbvet]

Put a throttle cable on the M813 with Cummins 250. Found a problem.
Truck idles right at 500 RPM. Pull up slack in throttle cable & go one notch more, & it goes to 1900 RPM!
Now I'm noticing, that with no load on it, it's almost impossible to throttle it up "a little" with the foot pedal either.
It's as if the engine wants to run away really easily, without a load.
Anyone else encountered this?
Eric
CBVET

 

[timntrucks]

i have only used the throtle alittle but mine im sure dont work like that. i will have to check that out.but with the pedel it comes up a little very easy i have the cummins m816 Tim

 

[73m819]

the hand throttle does the same thing on my 819, but the foot throttle works fine, i use a peice of wood to set the hand throttle, one of those things that i havnt got around to fix yet

 

[cbvet]

I just can't understand why it's doing this. The foot pedal & the hand throttle both pull the same rod on the injector pump.
I wonder about installing a longer arm for the hand throttle to connect to, so it wouldn't be so sensitive.
Eric
CBVET

 

[redass73]

mine does that as well, havent looked in to yet either. hope you find an easy fix.
rick

 

[jason@snakeriver]

On iniial start-up, after that thing warms up, you have to be right there or that son of a gun takes off on you. After it is warmed up, I have not experienced any problem on keeping a steady idle. Tom

 

[DaveP]

are you guys dealing with an axternal type govener? my 819 has a strange external limiting govener.

 

[cbvet]

I don't know! I'll get a picture when enough snow melts off the hood to get it open.
Eric
CBVET

 

[DaveP]

gov assy on my 819

 

[CGarbee]

It's my understanding that only the wrecker varients have the governor. The cargo and dump trucks I know for sure don't... Mine are also 'twitchy' when cold. I just play with the foot throttle until it's warm enough to use the hand throttle or drive... Afterwards, it'll idle just fine with the hand cable pushed all the way in... I figure that I'll play with the hand cable length one day when I've got nothing better to do to see if I can find a sweet spot for it, but it's not a priority.

I did find that my M817 has much better throttle response since I had the PT pump gone through, after thirty some years of use, it was pretty worn (before, it would run great over 1500rpm, nothing happening below that...), now, it runs like a champ all the way through the rpm range...

 

[m139h2otruck]

Somewhere in this 5 ton forum is a thread on Cummins engines and turning up the fuel, turbos, etc. The Cummins uses a different type of throttle than the multis and the Macks and tend to act different to the hand throttle positions. One of the members (supermechanic ?) has a lot of experience with these engines and would be the most qualified to discuss the fuel system and how it works.

 

[73m819]

my 819 has the ip as the other 809s except the 816, the -34p shows the same pump for all except the 816. dave, your 819 has the 816 ip ,the piston on the back is for the remote air thottle that the 816 has.

 

[DaveP]

well my set up on the 819 works to limit the rpm not increase it. before i turned the air to the cyl off it limited the rpms to about 1700. with the air turned off it runs like any other 250. maybe this is how they limited the top speed of the truck. when it (the gov) is working the trucks top speed is 44 mph. there is a speed limit of 35mph printed on the door. just my thoughts

 

[madsam]

Re: RE: Throttle adjustment?

the hand throttle does the same thing on my 819, but the foot throttle works fine, i use a peice of wood to set the hand throttle, one of those things that i havnt got around to fix yet

Is it a special mill spec piece of wood?

I do like the idea in the mid term. My cable is gone too.

 

[Gamagoat1]

DAVEP,
The 816 has a remote throtle lever in the wrecker bed. Pull this and the engine goes to 1650 rpm to assure a steady, smooth lift when loading ammo and the wife's furniture.

 

[DaveP]

DAVEP,
The 816 has a remote throtle lever in the wrecker bed. Pull this and the engine goes to 1650 rpm to assure a steady, smooth lift when loading ammo and the wife's furniture.

what limits the rpm's ? this gov that i posted the pic of? cause with air turned on to this cyl on the pump, the rpm's will max out at about 1700. on the 543 that i had there was a larger air cyl down under the cab that worked the throtle.

 

[Gamagoat1]

On the 816, its a valve on the power splitter, when it's engaged it extendes the limiter air cylinder.
When you pull the throttle lever on the wrecker bed, which is a wire connected to the throttle on the IP, the rpms go to 1650 and stay and is limited by this second gov.
On the 543, theres a switch on the wrecker control cab that controls this.

 

[jatonka]

I have an M543A2 that has a throttle lever at the drag winch operator's station. It connects to a cable that goes to the engine throttle lever, Isn't this original equipment? My manual says to set the throttle at 1000 rpm and use 4 th or 5th gear in transmission to run the wrecker. I have an air shift clutch lever at the drag winch station too, I'm a lot happier shifting this at 1000rpm than I would be at 1650 or 1700 rpm. I use this truck at work regularly and could stand to learn the tricks of the trade. I know it pulls good enough to fold up the ground spades. I'm looking for another set to modify a little. John T

 

[Gamagoat1]

On the 543 there was a switch on the wrecker ops control panel that set the second governor for wrecker, etc. ops.
I'm with you though, It works a lot better at a slower speed.
According to what I've read it was to maintain a steady smooth lift speed when moving bombs, rockets and other ord.

 

[DaveP]

I think old age is setting in. the cyl i spoke of that was under the floor on the 543 was for the air operated clutch!