Logo
Click for Detroit Diesel manuals!
Results 1 to 5 of 5
  1. #1

    Default 12V71 Fuel Modulator Timing

    Hi,

    My fuel modulators were disconnected after a recent rebuild. Its time now to reconnect and I was wondering what the timing measurement is?

    12V71TI
    Model Number: 7122-7302
    Serial Number: 12VA80373

    Thanks,
    Ozzy

  2. #2
    Join Date
    Nov 2009
    Location
    temecula, ca., usa
    Posts
    2,614

    Default Re: 12V71 Fuel Modulator Timing

    Just my opinion but I wouldn't want the modulators connected. They are nothing more than a piston in a bore with engine oil used as a medium for hampering the piston's travel speed. This action was intended to lessen smoke when the throttle was "firewalled" by slowing the rate at which the racks could move toward full fuel position. A device that is mo more effective at limiting smoke than a skipper that's easy on the throttles.

    But, I will get out my old service manual and look up the bleed orifice gauge size.

  3. #3

    Default Re: 12V71 Fuel Modulator Timing

    I tend to agree with you, however I would like them to be connected so I dont accidentally smoke out someone. LOL

    Thanks for looking this up for me.

  4. #4
    Join Date
    Nov 2009
    Location
    temecula, ca., usa
    Posts
    2,614

    Default Re: 12V71 Fuel Modulator Timing

    First off, are you sure you're dealing with a fuel modulator or is it a throttle delay? The terms are often comfused with one another.

    If it's a modulator, the adjustment is really simple. But first, you need to make dang sure there are no air leaks in the supply line from the air box and that the seal between the piston and housing is good. Meaning, that they aren't worn out.

    Unlike the throttle delay, if the modulator fails to actuate properly you will likely have very sluggish throttle response.

    If all's well there, you simply have the governor stop lever in run position and fuel lever in full fuel. Put a .454 delay gauge between the #2 left bank injector body and rack lever.

    Rotate the modulator lever clamp on the rack so that the roller on the lever contacts the "cam" lever that pivots on the modulator housing. Ensure the gauge is firmly held against the injector and tighten the clamp (gently now) and remove the gauge.

    All done.

    Good luck
    Last edited by jgmo; 05-16-2017 at 05:08 PM.

  5. #5

    Default Re: 12V71 Fuel Modulator Timing

    Yes.. It is the Modulator.

    I kind of agree with you, but sometime when you quickly accelerate because of accident or emergency you can smoke people out! LOL

    Thanks for the info!

Similar Threads

  1. 12v71 PTO's
    By aliboy in forum Detroit Diesel
    Replies: 0
    Last Post: 08-15-2014, 02:29 AM
  2. 12v71 - information
    By aliboy in forum Detroit Diesel
    Replies: 5
    Last Post: 06-29-2014, 02:09 PM
  3. 12v71 Natural
    By philtug in forum Detroit Diesel
    Replies: 3
    Last Post: 02-21-2011, 08:38 AM
  4. 12v71 air filter
    By ksl667 in forum Detroit Diesel
    Replies: 2
    Last Post: 12-03-2009, 11:26 AM
  5. 53 Hat 12V71 GPH
    By finatic in forum Detroit Diesel
    Replies: 4
    Last Post: 08-17-2008, 11:06 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •