idle adj.

[sawcut]

My truck idles to high (950 rpm). I backed off the idle screw,but the throttle cable doen't touch the screw. It's like the cable is too short! Is the throtle cable ajustable?

 

[Old Smoky]

The linkage is adjustable. The adjustment is located beside the pump, on the driver’s side. The threaded rod between the ball joints is where the adjustment is made. One end is left thread, and the other is right thread. All you have to do is loosen the jam nuts and turn the rod to make it longer, allowing the linkage to contact the low idle stop. Retighten the jam nuts once you are satisfied with the length, and you can now adjust the idle correctly, with the low idle screw. Be sure to be careful with the plastic ball joints. They have been known to break and you will be stuck at idle. Replacement metal ball joints are available.



Mike

 

[rowland]

Hey, I know that problem....

I have the same kind of problem. After 1. 5 turns on the power screw my idle wouldn't go down. I adjusted all of the play of the linkage as Smoky said. That worked for a while, but be careful or you will loose full throttle. I had to adjust the rest of the linkage to get full travel.



My question is: Does the the pump have and internal stop? Even with the linkage disconected I have trouble backing off enough.



What I ended up doing was letting off on the power screw and using the star wheel and smoke screw adjustments. I assume that somebody else has fixed this issue and I would like to know how its done.



Isaac

 

[sawcut]

problem solved

Adjusting the linkage was the fix for me ! What rpm's should I be at ? I am at 750 in D and 850 in park, soud about right.

 

[Old Smoky]

rowland,

Even with your linkage disconnected and your low idle stop backed out you can’t bring your idle down? There should be enough adjustment to get low idle, and a high idle of 3000 rpm +.



Sawcut,

I am not sure what the auto guys like, but my idle is set at about 850-875rpm. I think 750 rpm is the factory setting. So, anywhere between there and you should be fine.



As rowland, said it is important to check high idle (maximum linkage travel) after the adjustment has been made. I have found it is easiest to have someone push the go pedal to the floor while you make sure that the linkage hits the high idle stop screw. Something heavy to set on the pedal also works when you’re by yourself. Be sure that the floor mat is not interfering with pedal travel. If you turn up your rpms (back out your high idle screw), this should be checked again.



Mike

 

[rowland]

Currently with the linkage totally disconnected the stop dosn't even touch the idle screw. Thats why I assumed that there was some sort of internal stop. I should note that I didn't have this problem before I converted to the 7mm injectors. For some reason that brought the idle way up and dropped the power. Anyhow, my current setup works fairly well, I would just like to have the leeway to tinker a little more.



Isaac

 

[Grey Wolf]

Are you guys adjusting the idle on the pump? There is a jam nut and screw on the engine block side of the injection pump. I have a special wrench to unlock the jam nut that came from Cummins and that's how I adjusted the idle on mine

 

[rowland]

Yep...

Thats how I did it, only worked for a few turns though and then it quit contacting. I sure wish I would have had that special wrench of yours... . jamnut was tricky.



Isaac