How To Properly Tune A 12 Valve Cummins! (From The Expert Himself)

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Published 2021-02-17
Shows how to properly tune a 12 Valve Cummins from the expert! Wally has 1.2 MILLION MILES on his 93 1st gen currently mostly due to owning a hauling business in the 90’s. He still uses it to pull his 58 foot race trailer around to racetracks around the country.

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All Comments (21)
  • @xXnocturnumXx
    Just a correction: the deep grove of the fuel pin is supposed to face the front of the truck if you want full fueling, not the back as you stated. Also, back the smoke screw (low boost fuel control) flush with the cap to remove unnecessary smoke and adjust the star wheel (high boost fuel control) to clean up full throttle smoke. Smoke = heat and wasted fuel. You need to adjust the idle screw back to around 750 rpm after bottoming out the fuel screw and its recommended to have the intake boot off with something to choke it on first startup in case of a runaway.
  • The VE pump is different between the intercooled and non-intercooled 1st gen. Do not crank the fuel screw all the way down it will have a run away. I know from experience
  • @grantniemi8629
    If you want alittle more power you can also install a 3200 governor spring, the hungry diesel fuel pin, and bump your timing. Also you do not need that nylon bushing.
  • @jimmungai1938
    I highly highly recommend when you turn that star wheel down before you do that put some kind of a mark on the wheel to the housing before you do that that way if you for some odd reason or you need to or whatever turn it back to where it was you can do that in anyway but creating excess of smoke and stuff it’s just a waste of money man fuel washes your cylinder walls down and I’ll tell you something else it’s draws he taught us guys from the do you know the EPA in those gangsters anyway this is six in a row jim from Kennerdell Pennsylvania I got a 91.5 dodge give you three guesses what’s under the hood
  • @jesserasso1042
    Now you need to do the 1/8 inch timing bump jump the pump gear ⚙️ one tooth clock wise and a static timing plate
  • @DieselDethan
    Looks good to me except no reason to have the prebost screw cranked down with the sternwheel already bottomed out. Too much fuel at idle. And you may have or not have but the deep side of the pin goes towards the front of the truck.
  • @ricocoman
    Great video! Did I see this wrong but always thought the fuel pin ramp faced forward towards radiator?
  • @CUTTERUPROB
    i would be interested in a video on your trailer that's in the thumbnail
  • @keeprtuned
    Be sure to subscribe and I’ll put out more good videos!
  • @bigpapi1184
    So I’m planning on doing the same thing any way you can tell me step by step to make sure I do it right
  • If I put that spring up there it would be gone by the time I was to reinstall it. I always use magnetic pans.
  • @issatummins
    how do you know how much to unscrew the fuel screw
  • @CarsCumminsNCams
    That "clicker wheel" as he said wont turn for me, is there something I need to do first, or is there an issue with my VE pump? Does anyone know?
  • I know this is tuned for power, but how many mpg's does it get? Trying to tune mine after doing many upgrades and only getting 10 smh. Thanks!