HD emissions gurus: transmission controlled spark system 1983 3/4 ton 350

Discussion in 'The Garage' started by R72K5, Nov 8, 2003.

  1. R72K5

    R72K5 Banned

    Mar 5, 2001
    Likes Received:
    central IL
    ok 1983 HD 3/4 ton 350 with AIR and EFE and TCS and no EST system liek on 1/2 tons and cars, this engien does not have ECM controlled HEI or carb::

    -the tach terminal of the HEI cap is used with two smaller wires from it
    -small metal electrical control box mounted on driver side valve cover with several wires
    -electric oil pressure switch with several wires

    without finding and researching information on this TCS system, can soemone who already knows tell me how does this TCS system work ? it involved the SM465 and the oil presure switch and tach terminal of HEI and the metal box on valve cover, i assume that something is monitering engine RPM from the HEI cap and also monitering when tranny is in reverse and in low forward gear, i forgot if the system retards or advances timing, i am thinking retards timing, but whichever it does is aimed to reduce emissions somehow. i need to learna nd understand how it works in order ot know if maybe somehow a malfunction of the systemis causing my problem i am having with the engine,
  2. dyeager535

    dyeager535 1 ton status Premium Member

    Dec 13, 2000
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    Roy WA
    Re: HD emissions gurus: transmission controlled spark system 1983 3/4 ton 3

    My buddy has an '83 1 ton w/350/TH400, and the only emission "component" on his that resembles what you are talking about, was some sort of load compensation setup...if you were moving, and suddenly let off the gas, it would crack the throttle open a hair via a solenoid on the carb.

    Probably different setups based on engine, tranny, and destination, eh?

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