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Couple things on a 90 k5...

Discussion in 'The Garage' started by Emmettology 101, Sep 9, 2005.

  1. Emmettology 101

    Emmettology 101 3/4 ton status

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    Ok, so I am working on this new K5 I just bought.. A couple things I wanted to get others opinions on..

    This rig has sat for a while. It has been run here and there, but not often. I think it has sat at least 6 motnhs or so without starting.

    #1 - I am getting a very high idle. What would you check first? Bought some carb cleaner to spray in and aroudn the TB, thought maybe it was just sticky from not being used.

    #2 - I have to run one new tranny line. My local parts place had the right sized lines but wrong fitting ends so I have to use adapters. Bu they had only one. So I stopped at another store and they had one, but the inner hole is smaller. SHould I look for an adapter with the right inner diameter? A smaller hole will restrict flow and possibly bump up pressure.. Will it matter? These fittings/adapters will be on the tranny side.

    Thanks!
     
  2. Leper

    Leper 1/2 ton status

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    #1 remove old gas and get new gas in it. Let it run untill normal operating temp and then let it run for a while longer. Turn if off let it cool and then see if it idles high still.

    #2 Go to another parts house and get the right line with the correct fittings and throw the adaptor crap away.
     
  3. BigOrange90Jimmy

    BigOrange90Jimmy 1/2 ton status Premium Member

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    could possibly be a leaking TB base gasket. mine had that problem when I got it.
     
  4. Emmettology 101

    Emmettology 101 3/4 ton status

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    Ah, I forgot about the leaky tb gasket problems with these....... :thumb:
     
  5. 5kerblaz

    5kerblaz Registered Member

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    Agree with BigOrange. If the check engine light isn't on, the computer doesn't see a problem, and it's most likely a vacuum leak.
     
  6. southernspeed

    southernspeed 1/2 ton status GMOTM Winner

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    If your battery is a bit tired from sitting around the ECM will keep the idle high to try to charge the battery more. Just a thought!
     
  7. dave_90_blazer

    dave_90_blazer 1/2 ton status

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    the trans lines are 5/16 tubing, just get the pre flared brake lines from a purts store
     
  8. Emmettology 101

    Emmettology 101 3/4 ton status

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    Went and got different lines tonight. Funny. Autozone had the correct lines, but one of the smaller, "more knowledgable" stores didn't... :rolleyes:

    Also picked up a Fel-Pro TB gasket since it was only $1.99...

    We'll see.

    Oh, and the battery isn't very old. Brought it from home and pulled it from my pickup.. *shrug*...
     
  9. blazerguy 90

    blazerguy 90 1/2 ton status

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    When I got my 90 K5 a few months back it was running real bad, the first thing I did was give it a complete tune up, all the vacuum lines were shot so I replaced all of them, I removed the throttle body and took it all a part and cleaned it also did a couple of performance up grades to it. I also replaced the coolant temperature sensor, thermostat and up graded to a heated oxegen sensor, it runs real good now. still a few minor bugs im still trying to track down, but it runs good.
     
  10. jekquistk5

    jekquistk5 Weld nekid Premium Member GMOTM Winner

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    I love my 90, but I need to fix the tranny, and get a new torque convertor in there and it should be good.
     
  11. Derf00

    Derf00 1/2 ton status

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    If your '90 has a cruise control check the linkage and make sure that at idle, the vacc diaphram is allowing the throttle linkage to go to its lowest setting. Had this very problem on my '90, and it took a while to find it.
     
  12. Emmettology 101

    Emmettology 101 3/4 ton status

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    Yesterday I got the new tranny line run and figured I'd start it up to make sure it didn't leak. Well my new line didn't leak, but now my fuel line does. :doah:

    I smelled gas really bad and looked under neather to find gas all over. :(

    So that is my next fix.

    Anyone use regular rubber line on a TBI? I thought about getting a regular steel line and run it as far as I can and the connect it with rubber.

    TBI is only aroudn 15psi, so would it work?
     
  13. BigOrange90Jimmy

    BigOrange90Jimmy 1/2 ton status Premium Member

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    if you need some of the factory braided lines that run from the TBI to the frame, i have one i'd give you for the cost of shipping....PM me and let me know.
     
  14. dyeager535

    dyeager535 1 ton status Premium Member

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    Depends where it's leaking as to whether it will work or not. I'm not a fan of rubber ANYWHERE, there's a reason GM didn't do that on TBI setups.

    In any case, you don't want rubber around heat or somewhere it will move and rub on anything, or it will eventually be cut through and you end up with a pressurized fuel leak.

    Problem with TBI stuff is that the fittings are unique and not something you can just go buy and fix "right". So either you replace the whole line, or come up with another way to do it.
     

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