261 idles fast

[xxxsandman]

I have a 261 with a 4 cylinder perkins. It idles normal with a slight lope when started cold, but after it's at operating temperature, it idles high (1,200 RPM or so). Also when I pull the shut off cable it takes 10 to 15 seconds to finally wind down. It does not smoke at all. It doesn't show any signs of engine wear. It has 1,200 hours on it.

I tried adjusting the idle stop on the injection pump, but that did not change it at all.

Any suggestions on what it could be and how to fix it?

Thanks!

 

[JerryG]

I have replaced a ton of clutches on 100 and 200 series as well as just about everything else you can do to them, but I'm not worth a flip when it comes to the fuel pumps. I just didn't have any interest in the fuel system when I worked at a dealership. I wish I had of took more interest in them now. Why don't you e-mail Big Dean Austin and see what he has to say about it.

 

[GaryCrowell]

This is kind of a lame recommendation, but you'd be suprised how often it changes things. I'm no diesel expert, and I'll admit that diesel injection systems have a certain amount of "voodoo" associated with them for me. Any time I have one running funny like yours is, the first thing I do I put in a new fuel filter and dump some diesel injector treatment in the fuel tank. Crud (technical term) can do weird things to a diesel, often times this will fix it. It's worth a shot.

 

[xxxsandman]

I already put a fresh fuel filter on it and put a heavy dose of Lucas Fuel treatment/injector cleaner in and have ran about half of the tank out already. No change.

It seems the idle is directly releated to how hot the engine is. The hotter the engine, the faster the idle. When started cold (90 degrees outside) it will idle at about 800 RPM, which seems about right. It does have a little bit of a lope to it at lower RPMS while cold. It has this lope until about 1,300RPM, then it's smooth.

Once warm the idle lope is gone, maybe because it idles at 1,200 to 1,500 RPMs!

Also it can take 15 seconds or longer to die when I pull the kill cable. The cable is making the lever on the injection pump travel all the way.

I have no idea what it is, but it sounds injection pump related or maybe something to due with the mechanical lift pump? No idea what to try or do. It's usuable like it is, runs good at working RPMS, but the high idle makes putting it in gear a grinding event usually and is irrating.