IP Throttle Advance: Mechanical vs Vacuum Actuated

Discussion in 'VW Mk3 Jetta, Passat TDI and other/older diesels' started by eaders, Dec 16, 2017.

  1. eaders

    eaders New Member

    Joined:
    Nov 25, 2017
    Messages:
    5
    Car:
    VW 1982 Vanagon L with [1993] 1.9L IDI (AAZ)
    Location:
    Calgary
    Hello,

    I did an honest and thorough search and could not find what I needed...

    I am currently doing an AAZ rebuild. I have two IPs; 1) from a 1.9B/1.6H hybrid in a Vanagon custom project by the PO; and 2) another from a stock 93 Passat. I will be using the IP from the Vanagon as it has an LDA/BP and I was told that the Passat pump is an ECO model.

    The Vanagon pump (286) has a mechanical spring loaded lever for the Throttle Advance. The Passat pump (323) has a vacuum actuated Throttle Advance. My understanding is that this vacuum actuator was tied into the EGR system (with the valves for vacuum being controlled electronically from the glow plug relay). However, I am not installing an EGR system on my new rebuilt motor.

    So, what I want to know is, would it be beneficial to transfer the Vacuum Actuator from the 323 pump to the 286 pump for Throttle Advance? It will fit externally but can it be done without opening the pump up (i.e. changing internal parts)? Or would it be better to just leave the 286 pump as a mechanically controlled TA?

    Also, could someone please confirm my understanding that the Throttle Advance is used in situations of high load to allow for proper fuelling? If so, I would want to tie the Vacuum Actuator lever into something that pulls high vacuum under load? Are there any other situations you would want Throttle Advance?

    Thanks for the help friends!
     
    Last edited: Dec 16, 2017

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