Rebuilt Injector pump idle way high 2200rpm

[ross165123]

So I sent my injector pump of to superior diesel in South Carolina for a rebuild, got it back today to find that my idle was at 2200 rpms. my first thought was I set the pedal linkage wrong so I just took it off and had my wife crank it. so there I sit with the engine revving like **** and when you turn the throttle it brings the rpms up even more. So as instructed my wife cut everything off and pulled the fuel shutoff when the rpms started to increase. Any ideal on what I might have done wrong other then the most obvious as the idle was set wrong?

 

[WillWagner]

What engine are we talking about?

 

[Two Stroke Madness]

Make sure your fuel return line is not blocked or kinked. That could result in a high idle situation.

 

[ross165123]

250 cummins

 

[sandcobra164]

If the idle is set slightly high and the truck has some suction line air leaks, it can do the same thing. I have never understood how that happens on a 250 Cummins. I would think introduction of air into the fuel at high idle would cause a stall. Now that I have my M923, it has throttle response and return to idle as crisp as my old Deuce but I have had quite a few M809 series trucks out here that would lag on acceleration, wind up to the governor setting, and slowly settle back down to idle when let off. Once fuel lines were replaced, all went back to normal on the M809 trucks. Hard to find the leak as the fuel lines are suction lines on these.

 

[ross165123]

I fixed all the air leaks from the injector pump to the tank. Replaced fuel hoses, then I plunged the breather on the firewall by the horn and caped the line where it connects to the pump. Then I connected a regulator and a air hose and let about 20psi at it. Replaced the o-rings on the primer pump and tank selector and still was losing prime so last but not least sent a spare pump for a rebuild why I limped on with the leaky pump. After all that I hope it isn't an air leak. I will check for a cloged return line when I get a chance tho.

 

[Floridianson]

Did you remove the arm from the throttle shaft or did the shop do it.

 

[ross165123]

I have no clue about that, I installed the pump primed it with a few squirts from a 60cc sering and bam fired right up to 600 and kept going

 

[ross165123]

sorry yea I removed the throttle arm

 

[ross165123]

Well I couldn't find anything that was wrong so I took it off and shipped it back to Superior Diesel. I looked for air leaks again by caping of the supply, return, and vent line and pressurizing the system but I found no leaks. I did tho find a spot in the return line where it had been pinched so I fixed that and still 2200rpms. Thanks for all the ideas guys ill let you know what it was when the problem is resolved.

 

[ross165123]

Now USPS has lost my pump in the sorting hub here in VA. They said they will contact me in 2-3 business days.... What crappy luck ive had.

 

[ross165123]

Get the pump back after usps lost it for about 2 weeks. Superior Diesel said there was nothing wrong with the pump so they did not refund my shipping but somehow this time it worked flawlessly. I wish I could tell you what was wrong but I have no clue, but the truck runs great now it finally dropped a pair!

 

[simp5782]

It was a stuck plunger more than likely. They took it apart I'm sure and set it how it was suppose to be. Since it was nothing "they did" they won't bite the bullet. I just had the same thing happen on a pump I had rebuilt.