bending and adjusting new choke thermostat rod

Discussion in 'The Venerable Q-Jet' started by TTNC, Oct 23, 2014.

  1. TTNC

    TTNC Well-Known Member

    Just finally had installed a qjet (7040240 I believe) rebuilt by Cliff a couple years ago. Had to use a half inch spacer underneath the carb to have room for the TV linkage for the trans, but the shop that installed it did not lengthen the rod for the divorced choke coil, and so the carb runs fine but the choke is behaving funny, so I have to bend up a new longer rod.

    Whats the starting point to do this? I've read elsewhere for some other qjet the procedure was to push the rod all the way down into the coil housing and then bend the rod so that the top of the rod is level with the bottom of the hole in the linkage that it goes into, but I'm not sure if that is applicable to mine. I'm also gonna assume the fast idle cam is in the highest position (all the way counterclockwise?) when this is done. Does this all sound correct or should I do something differently?
     
  2. TTNC

    TTNC Well-Known Member

    Pic of the current setup, and yes I've capped off that open vacuum port:

    [​IMG]
     
  3. techg8

    techg8 The BS GS

    can you disassemble the choke thermostat and duplicate the rod, but a half inch longer?

    I believe the correct way to adjust the setting is to do it when the car is cold.

    push the choke arm up and get the cam on the hi step.

    Then the arm should be bent/adjusted so it swings freely into and out of the GAGE slot on the choke arm.

    Once this setting is made you can install the rod into the choke arm STD hole.
     
  4. TTNC

    TTNC Well-Known Member

    I hope it's that simple. However, when I disconnect the rod I have now from the STD hole that it is in now and fully close the choke, and with no force being applied to the choke spring, the end of the rod is less than half an inch away from the STD hole. I bought this choke coil off a board member here so I do not know how original the rod with it is. It doesn't look that old. With the rod disconnected from the linkage, using my hand I can make the rod move up an down with about an inch or so or travel.

    More confusion is caused by things like this which is supposed to cover 4MV carbs: [​IMG]

    Procedure for the above is here:

    When they say the second step of the fast idle cam, it sounds like they mean to turn it all the way counterclockwise and then back clockwise one step. Does that sound right?
     
  5. techg8

    techg8 The BS GS

    that illustration of the choke linkage is a chevy choke and link but the principle is the same.

    Yes they mean hi step minus one.
     
  6. TTNC

    TTNC Well-Known Member

    So, today I attempted to make a rod that would meet the above requirements. The above image tells you to push the rod against the bracket directly underneath the coil, but as it turns out I have no such flat bracket under the coil. To make a long story short, the rod I already had was the perfect length if you don't push down on it as instructed but rather leave it with the rod sticking out of the housing and just hanging there freely. I do think however that the rod was not connected properly to the coil spring which accounted for the funny behaving choke. Seems to work fine now.

    The carb itself seems to fun fine and idles about 700 or so, but when I get the car warmed up and then really step on the throttle and then let off, the throttle sticks. I shift it into neutral so the car doesn't get away from me, slow down a bit then shift it back into drive. Engine speed comes back down to a more reasonable 1200 or so and stays there even when stopped at red lights. Get the car back home, let it cool down, go to drive it again, and it behaves fine as long as I don't bury my right foot.

    Any ideas? My first thought is the fast idle adjustment screw behind the forward choke pull off which I haven't played around with yet, but given this is a fresh Cliff rebuild I don't want to adjust anything more than I have to.
     
  7. TTNC

    TTNC Well-Known Member

    Couple other things...I pulled over to the side of the road to see if I could push down on the fast idle cam to lower the engine RPM but the cam was already down all the way/ rotating freely. Also when I put my foot in it the power felt like it leveled off earlier than it should...throttle plates getting stuck on the spacer maybe?
     

Share This Page