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CAT 951C Runaway Throttle

frogdiver04

Member
Joined
Sep 20, 2018
Messages
5
Location
Virginia
Hello All,

So this is my first thread and this is all new to me. I have some background in working with diesels on generators but not enough to tackle this.....lol. So I just recently purchased a CAT 951C with a 3304 no turbo. Starts up on first try, no unusual smoking, solid machine. It does have one issue that worries me a little. Every now and again it will throttle up on it's own. I can move the throttle down to shut off and it will shut off. What I normally do is throttle down to shut off and wait till it throttles down then put it back in idle. Sometimes it will be ok and sometimes it will throttle right back up. It happens sporadically but not very often. It seems like when it has a load on it, it rarely does it. No load, it does it more often. I haven't done anything to it yet or done any troubleshooting. The guy I bought it from knew of this problem and told me and he managed it the same way. But like I said it doesn't happen that often so it's manageable. I want to fix it so it doesn't turn into a bigger problem in the future. I've looked all over the internet and haven't come across much. Any help would be much appreciated.

Thanks,
John
 

sealark37

Well-Known Member
Joined
Jun 3, 2012
Messages
120
Location
Davidson, NC
Occupation
Retired pilot, old equipment mechanic
Find yourself a Cat service manual on fleabay. It will take you through the troubleshooting steps.
 

thepumpguysc

Senior Member
Joined
Mar 18, 2010
Messages
7,597
Location
Sunny South Carolina
Occupation
Master Inj.Pump rebuilder
Is the throttle actually moving.. have u tried adding a spring to the lever, pulling it to low idle position.??
either that or It sounds like the pump governor is "wonky".?? & its not really something an owner should tackle..
I'd be REAL CAREFUL.. cuz IF it sticks, its gonna be VERY costly.!!!
 

frogdiver04

Member
Joined
Sep 20, 2018
Messages
5
Location
Virginia
Is the throttle actually moving.. have u tried adding a spring to the lever, pulling it to low idle position.??
either that or It sounds like the pump governor is "wonky".?? & its not really something an owner should tackle..
I'd be REAL CAREFUL.. cuz IF it sticks, its gonna be VERY costly.!!!

The throttle lever doesn't move. Good to know. I will definitely be careful and I will get it looked at ASAP. Definitely don't want it to stick. Thanks a bunch
 

RZucker

Senior Member
Joined
Jul 7, 2013
Messages
4,077
Location
Wherever I end up
Occupation
Mechanic/welder
The throttle lever doesn't move. Good to know. I will definitely be careful and I will get it looked at ASAP. Definitely don't want it to stick. Thanks a bunch

Ran into this on a D4H with a 3204 engine, had Cat check out the governor, it had some broken parts and was about to be a major unstoppable runaway...
 

frogdiver04

Member
Joined
Sep 20, 2018
Messages
5
Location
Virginia
Ran into this on a D4H with a 3204 engine, had Cat check out the governor, it had some broken parts and was about to be a major unstoppable runaway...

Thanks for the info. I'm having CAT come out and look at it soon. That's what they were saying too.
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
29,696
Location
G..G..G..Granville.........!! Fetch your cloth.
If you're in any way mechanically inclined the members here could guide you through how to remove the fuel pump & governor. There is also a resident fuel injection pump specialist based only 1 state away from you (SC) who could likely sort it for you for a fraction of the cost than having Cat do it.
 

frogdiver04

Member
Joined
Sep 20, 2018
Messages
5
Location
Virginia
If you're in any way mechanically inclined the members here could guide you through how to remove the fuel pump & governor. There is also a resident fuel injection pump specialist based only 1 state away from you (SC) who could likely sort it for you for a fraction of the cost than having Cat do it.
I appreciate the info. They guy I know is a good friend and he is going to look at it for free and help me fix it. I just have to pay for parts.
 
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