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.

TBI qusetion

Discussion in 'The Garage' started by Wingnutt, Oct 25, 2003.

  1. Wingnutt

    Wingnutt 1/2 ton status

    Joined:
    Feb 20, 2000
    Posts:
    324
    Likes Received:
    0
    Location:
    NOVA
    I'm hoping that somebody can answer this. The bushings that guide the throttle shaft on the base of my '88 350 TBI have worn odd and this causes the throttle to stick open slightly (1200-1500 idle). I can get the idle back to normal by giving athe throttle a quick stab (like kicking off an auto choke). This is agrevatting to say the least. Does anybody know where I can get these bushings? GM neven made them, and all I get at the local parts stores is the deer in the headlight look when I explain to them what I want. If nobody knows, does anybody have a decent TBI they want to get rid of? TIA
     
  2. bigblock454

    bigblock454 Clack Clack Clack Premium Member

    Joined:
    Jun 18, 2002
    Posts:
    546
    Likes Received:
    16
    Location:
    Terre Haute IN
    Even if you could find them you wouldn't be able to accuratly position them without a vertical milling machine. contact turbocity.com they have some bare units for $200 I think.
     
  3. bablazer73

    bablazer73 1/2 ton status

    Joined:
    Apr 4, 2000
    Posts:
    3,363
    Likes Received:
    0
    Location:
    upstate ny
    I had that same problem. I couldn't find anybody willing to do it for me. None of the machine shops would. I didn't check with turbo city, but a buddy of mine got some from them for his 84 vette (twin T.B.I's). They were better than stock. I bought a holley "performance" replacement for 380.00.
     
  4. tarussell

    tarussell 1/2 ton status

    Joined:
    Dec 28, 2002
    Posts:
    1,354
    Likes Received:
    0
    Location:
    Bagdad , FL
    You may also want to try Howell Engine Developments INC. - I just got some stuff from them for my TBI and they were very helpful. I know they sell new TBI units but they may sell recon ones too.
    HTH , Tom
     
  5. ntsqd

    ntsqd 1/2 ton status

    Joined:
    Nov 28, 2002
    Posts:
    3,381
    Likes Received:
    0
    Location:
    So. CA
    Couple of thots:

    Are you sure that's the cause of the problem ? Sometimes soft carbon builds up in the throttle bore and causes exactly the problem you're descibing. Some carb cleaner and elbow grease will cure that.

    If it is the throttle shaft bushings, they are likely a common size. Check with a carb shop as they should have the K-Line kit for putting bronze thin walled valve guide bushes in throttle shaft bores. It's very common to have to do this to Holley Carbs, some of the custom shops do it from the start.
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,975
    Likes Received:
    189
    Location:
    Roy WA
    Carbsunlimited sells bushing kits for the quadrajets, I'd bet there is a kit for the TBI's as well.

    I can't comment on how straight you can drill, but with a large pilot hole and non-guerilla force, you should be able to drill them straight no problem.

    In the Q-jets, the primary throttle shaft *drivers side* ONLY needs to be bushed, because all of the load is carried there...just like an alternator, only the loaded bearing surface typically wears out.
     

Share This Page