PORPRES asks about:...Idle Down Instructions.........

[BushWakr - RIP]

I have pasted the following thread here, from the FAQ section for better/proper Forum exposure... .

pb.







"... ... I just turned up the full power screw. Can someone tell me how to turn down the idle?... . "



Thanks Much

 

[tugboatphil]

That is the Question!

From the day I bought my 93, I had an idle that was already too high. I have no tach, but she did not have that Cummins rythm to the idle. I also had a severe lack of power. The PO had been into the pump, so I had no idea where to start. I ended up having to turn in the fuel screw almost 2 turns, just to have power enough to climb the hills around here. I had the low idle turned in to where the throttle lever didn't even touch it.



I just got done having PODs installed and the pump tweaked. I finally had enough power to where I could back out the fuel screw enough to bring the idle down. In fact, with the new injectors and pump mods, I was burying the pyro going uphill. Now she'll only go to 1450, but I still have to watch my right foot.



While inside the pump, Greenleaf said that the fuel pin wasn't moving as freely as it should have. Was that part of the problem, I don't know. The old injectors were not severely carboned, but did have some build-up. I also put a new lift pump on, but was not able to test the old one prior to removal.



I recall a couple of others posting that they had an overly high idle, but don't remember anyone finding the "one" thing that was causing it.

 

[ARedetzke]

You need to back out the low idle screw on the top/backside of the pump. Work the throttle linkage by hand and look for what stops it. It is a long screw located between the block and the AFC housing. The best way to get the lock nut loose is to use a long punch and a hammer. Then just back it off to where you want it. It should be somewhere around 750-800 RPM if I remember correctly.

AJ

 

[BushWakr - RIP]

Normally the idle changes with fuel screw adjustments... basically it tricks the internals into thinking it should be idling higher... sorta...

If the low idle screw doesn't allow enough idle adjustment then you need to look at the throttle rod with the two "ball ends".

That shaft is threaded (left hand I believe). You loosen the two locknuts, and lengthen the rod a bit. This will allow the low idle stop plate to mover further back and contact the low idle screw end. Once you are making contact with the low idle screw, tighten up the two locknuts on the throttle rod and you're good to go.

You'll have to do this on occasion if you tweak and tune back and forth to get the fueling were you want it.

Keep in mind that the throttle shaft should touch the low idle screw AND the high idle screw (aka: governor screw)..... well, ok, some of us don't use a high idle screw but that don't count. .



pb... .

 

[Greenleaf]

What's a *High Idle Screw* ? I don't think my pump has one. Oh wait, I lost that when I had my pump apart ... ... ..... darn small parts, anyhow.



-S

 

[JLEONARD]

high idle, but don't remember anyone finding the "one" thing that was causing it.

Gotta lift up a little on that right foot!!! That'll get the idle down! :-laf

 

[PORPRES]

Thanks Bush!

 

[BushWakr - RIP]

... . any time bud...



Scott, I lost my screw too... . 'course my wife insists ALL my scews are loose to begin with so no surprise I lost one...



pb...