Kickdown

Discussion in 'The Venerable Q-Jet' started by batsong, Mar 31, 2009.

  1. batsong

    batsong Well-Known Member

    Does Q-Jet calibration have anything to do with the kickdown on a TH400?
     
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member


    No
     
  3. batsong

    batsong Well-Known Member

    What about the vacuum line to the trans?
     
  4. Schurkey

    Schurkey Silver Level contributor

    Modulator affects upshift. Electric solenoid accomplishes the kickdown.
     
  5. batsong

    batsong Well-Known Member

    Thanks for the replies. Don't mean to ask so many questions. This car has been a learning experience!
     
  6. copperheadgs1

    copperheadgs1 copperheadgs1

    Make sure switch on gas pedal is working.
     
  7. batsong

    batsong Well-Known Member

    Thanks. I've been through the switch - even bypassed it. Added new wires all the way down to the trans. Figure that at that point it's either the solenoid in the trans or a vacuum thing.
    My vacuum modulator is not locked in position. Was does turning it do?
     
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member


    What do you mean it isn't locked in position? It is being held in the transmission with a clamp and bolt, right?
     
  9. batsong

    batsong Well-Known Member

    It has a clamp and bolt, but I ca turn it. Does turning it do anything, or is the clamp simply to hold it in?
     
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member



    No, the clamp and bolt hold it in. Some people have been known to cross thread the bolt and break the case casting. I just wanted to make sure you didn't do that. Troubleshooting the kick down is very simple. If you are sure that 12 volts is being passed to the transmission by the gas pedal switch, check the down shift solenoid in the pan. Use a jumper wire from the battery + to the contact at the transmission. Listen for a click. No click, the solenoid is bad, or the wiring in the pan is bad.
     
  11. 70sLark

    70sLark Well-Known Member

    could fubar the o-ring on it turing it but thats about it.

    I had mine held on by a bunji cord for a bit.

    th350/th400 vacumm mod is the same.

    Now if you got an adjustable one, you remove the vaccum hose and turn the screw that is inside the vacuum port nipple.
     
  12. batsong

    batsong Well-Known Member

    Thanks everyone. I'll check this stuff out.
     
  13. batsong

    batsong Well-Known Member

    The solenoid was good. The switch - good. Turns out that it was the wire from the trans was grounding out and the wire from the fuse box was dead. Both wires!
    When this car was new, it had so many amenities that it practically talked to you as you went down the road, now I find myself talking to it!
     

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