fuel screw?????

[J-link]

Finally got around to turning in my full power screw tonight, made it in two whole turns b4 I ran out of idle adjustment


I've read of ppl removing a collar on the screw that has an o-ring


Their not talking about this are they?




Do I need to put that o ring back on? It was in-between that clip and the lock nut



TIA. -Justin

[CumminsPower59]

That looks like the tamper collar that comes on the fuel screw. That o-ring however, not sure what that is about. The o-ring that is on the fuel screw is much smaller and it is in a groove on the fuel screw, inside the AFC housing. Some people tear it when the fuel screw stops and they try turning it more.

You are good to go

[CumminsPower59]

On second thought, that big o ring may have something to do with the tamper cover...

[J-link]

You mean like maybe it was in there to fill some space and keep the cover from vibrating?

Or like seal it some how?


I like the sound of the first better

[RCCUMMINS89]

I've never seen the big o ring before??????????????

[J-link]

The o-ring was in-between the lock nut and the tamper collar ?????



I guess the pump was rebuilt at some point in its life and its something that got put on

[PToombs]

Maybe somebody had that on to hold the tamper cap, so it looked untouched by human hands, or grubby fingers!

[J-link]

Maybe, I only got two turns out of it b4 I ran out of idle adjustment to bring it back down



Then again with two turns my egt's at WOT are still only 1000-1100* and 21 psi of boost





Does 250* hot idle sound right???


Thanks - Justin

[RCCUMMINS89]

Most trucks idle at 300.... Every truck I've owned has been able to get 35ish psi out of a stock set up and cranked in power screw.

[RCCUMMINS89]

When you say idle adjustment.... You did lengthen your throttle rod, correct?

[J-link]

No sir, but the plate the throttle rod is attatched to is resting on the idle screw, I could probably turn it out another 1/8 inch if I took a couple lines off



I didn't think I needed to mess with the rod since it was idiling down when I turn the screw, but it is about a 1/8 inch from whatever line is right behind it and I can't get it to turn any more and I didn't figure that little adjustment was worth taking the line off

[93flatbed]

Your hands are dirty!

[J-link]

Haha yeah apparently I have a minor exhaust leak in between my downpipe and my exhaust housing.


Who knew working on a diesel would be such a dirty job? Someone needs to call Mike Rowe

[J-link]

I know this is a old thread, but my pump has started leaking form the fuel screw (at least that's where it looks like its coming from) and idk what to do.

should I take the screw out and replace that o-ring in there, or maybe try to sandwich a crush washer in between the lock nut and the pump?

I bought a re-seal kit hoping I could fix it quick and easy myself, will the screw come out with everything in the truck and is there anything in there that may mess up by taking it out?

[BC847]

There should be an O-ring nested in a groove on the main fuel screw . . .