hoodeleydoo

1976 Fleetstar 855 cummins (270) idle adjustment help

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hi guys,

I think im going to try to adjust my fleetstar idle. I have fresh fuel in it and have been using some fuel treatment cleaner (Lucas). 

its still too low. I think an additional  100 or 200 rpm would be just great - it would take the shakes out of the cab (so much I can see out the mirrors) as well as help with the shifting.  I thought about limiting it with the pedal travel but thats not the proper way.

so there is a tool to do it while running or you can do it by small adjustment when off then start er up and see. i dont have the tool but pretty sure I can make one.

 

anyone have any advice or experience using the tool or not? any advice on any idle adjustments? I also heard that possible injector pump pressure adjustment may help but i'm not too keen on that.

The engine runs out just great so I dont think there is an injector or injector pump/pressure issue.

Thanks!!

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This might help 

 

59c2a8ac109db_cumminsptpumpdiagram.gif.4f5659b2c8d3f3b557bcea0093a66ccd.gif

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Hi thats perfect. Happen to know how sensitive the idle is to turns of the screw?

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Hoodeleydoo

       If you will remove the 1/8" pipe plug in the rear of the governor housing,  you can insert a small screwdriver and turn the idle screw aprox. 1/4 turn clockwise.  The best way to do this,  is like you suggested,  build a round shank screwdriver with a brass fitting and equip this fitting with an O-ring.   Install this tool in place of the 1/8" pipe plug.   Run the engine and bleed the air out of the fuel system by reving up the engine a few times.  Then screw the idle adjustment screw in to set the idle speed so that the mirrors don't shake.

     If you don't want to build the special tool, you will have to guess how far to adjust the screw.   Remember to bleed the air out each time and see how well it idles.

GT&T

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Howdy guys - thanks for advice - just what i needed. i'll end up making the tool and giving it a go this winter.

the sensitivity of the screw turns vs engine speed was of interest - bleeding the system warning is the added bonus!! 

kevin

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Hoodeleydoo

      I didn't want to make a big deal out of bleeding the PT fuel pump.    I did want to make you aware of the fact that when there is some air in the fuel  on the PT fuel system the Low idle and High idle speeds will fluxuate until the system is completely free of air bubbles.   The PT fuel system is very easy to bleed.    

     The nice thing about using the idle speed adjusting tool is, you have the ability to turn the tool one notch at a time  ( up or down) until the perfect idle speed is reached,  ( mirrors quit shaking ).  

     It was nice of Kevin to post the cutaway of the PT fuel pump.  Thanks.

GT&T

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Hi GT&T - no big deal - all good. thanks for the feedback. its nice to chat about hings before doing them!

thanks

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