Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

EGR Valve

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by Johnny Buck, Apr 5, 2002.

  1. Johnny Buck

    Johnny Buck Newbie

    Joined:
    Apr 5, 2002
    Posts:
    2
    Likes Received:
    0
    Location:
    Winston-Salem, NC
    On my rebuilt 72 454 in my Jimmy, the EGR valve has always been capped off ever since I have had it. I was wondering if this was a good idea, if it will do any harm or hurt/ help performance, etc. If it should be hooked up a vaccum fitting on my Q-jet, which one should it be on? Thanks a lot for any help.
     
  2. Triaged

    Triaged 1/2 ton status

    Joined:
    Feb 21, 2001
    Posts:
    3,808
    Likes Received:
    0
    Location:
    CA (LA/OC area)
    The EGR (Exhaust Gas Recurlation) is only for emitions. It will not hurt to not have it hooked up if it is blocked off well.

    The PCV (Positive Crankcase Ventilation) has to be hooked up...
     
  3. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,063
    Likes Received:
    70
    Location:
    Pleasanton, CA.
    I do not believe that a "72" even uses an EGR valve, I think you might have a later manifold on an early engine. I am pretty sure that EGR valves were not even used until around "75" or so.
     
  4. Burt4x4

    Burt4x4 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    6,854
    Likes Received:
    0
    Location:
    California (Modesto area)
    Yup, No EGR on 72. Most likly someone swaped the manafold or the whole motor from a later modle....
     
  5. Steve_Chin

    Steve_Chin 1/2 ton status

    Joined:
    Mar 6, 2001
    Posts:
    1,126
    Likes Received:
    0
    Location:
    Foster City, CA, USA
    The first year for EGR in most GM divisions was 1973.

    EGR won't really hurt a lot of performance since it's vacuum-triggered. When you have the throttle mashed, your EGR is pretty much non-functional. Since its main purpose is to reduce the combustion temperature (in order to reduce NOx emissions), it can actually reduce the tendency for an engine to detonate under moderate throttle loads.
     

Share This Page