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Why is my blazer idling so high, Throttle Body Spacer maybe??

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 90blzr, May 31, 2001.

  1. 90blzr

    90blzr 1/2 ton status

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    I have a 350TBI with a K&N, Helix throttle body spacer, and other than that its pretty much stock. Lately, it seems to be idling high every now and then. It usually idles at around 600 I believe. Every now and then it gets up to 900-1000rpm's like after I'm on the gas for a while and then slow down to a light or stop sign. It's like my foot is still on the gas a little, but its not. By the way its automatic. Would it have anything to do with the TB spacer? Any adjustment for it being higher than normal for the cable. Havent really checked it out to close, I thought I'd get some ideas of what to do first. Can anyone help me? Also since the TB spacer install, the tranny shifts at higher rpm's and harder than it did before, possibly spacer related also?. Any help is appreciated.
     
  2. MaxCrack

    MaxCrack 1/2 ton status

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    Does it go back to normal if you quickly hit and release the gas pedal?

    That's because I'm the devil.
     
  3. Pure Insanity

    Pure Insanity 1/2 ton status

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    did you space up the cable bracket also?it might be binding occsionally.my dad put 1 on his truck and he spaced up the cables also.he never had a prob w/ his.but this is the only way a spacer would affect it that i can think of.

    PURE INSANITY
    86 blazer see it at:<A target="_blank" HREF=http://www.zing.com/album/pictures.html?id=4292792569>http://www.zing.com/album/pictures.html?id=4292792569</A>
     
  4. rampage

    rampage 1/2 ton status

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    I use to have a high idle (1400 rpm) and it wouldn't pass CA emissions. Through many responses it was suggested to spray carb cleaner around the TBI unit where it mounts to the intake to see if the rpms jumped up. Sure enough, it revved up a little bit. I replaced the gasket ($10) and it passed emissions with flying colors. This is the first thing I would check since a can of carb cleaner is $2 and it takes about 5 mins to see if that's the problem. Since yours is only happening occassionally I'm kind of doubtful if that is your problem ... but it's worht the effort.
     
  5. 89Blazin

    89Blazin 1/2 ton status

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    Sounds like the idle problem and tranny shift changes took place at different times. Both not immediately apparent after the spacer. The tranny my not be related and just a coincidence. I'd check the tranny out good, fluid, filter, modulator...I'd also check my vacumn system, maybe the computer is tryin to compensate for something abnormal. Another thought, maybe the throttle position sensor is goin south slowly. Or a sticky cable as was already suggested.

    85 Burb and an 89 Blazer
    One just for fun, one simply for pleazer
     
  6. 90K5

    90K5 1/2 ton status

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    Check the cable. Mine sticks too sometimes. Just put some grease on the linkages.

    90K5

    See my truck at <A target="_blank" HREF=http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502>http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502</A>
     
  7. 90blzr

    90blzr 1/2 ton status

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    MaxCrack- no if I give it gas real quick it just drops back to high idle.
    pureinsanity- no I didnt space the bracket. Do you mean at the back of the intake? I think thts where its bolted down anyways.
    89blazin- how do I check the throttle
    I called and asked about the tranny shifting hard and they said yeah you have to adjust the tranny cable/line. But they said to push in the brass colored botton and pull the tranny line. I dont know what the hek they are talking about, anyone else know?
    rampage- I'll try that this weekend.
    89blazin-how do I check the throttle poition sensor and modulator? I jut changed the fluid/filter rescently, not too dirty and still pretty red.
    Anymore suggestions? Thanks to EVERYONE!!
     
  8. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    With FI systems, the more air that is sucked in, the computer will add more fuel. Check for leaks like a previous poster suggested first, seems gaskets go out all the time. Then check the throttle cable for binding. A TPS is hard to check unless you have a multimeter or scanner. TPS is also adjustable. Loosen it up and move it a little.

    "Liberals ain't mean, they just don't have any common sense!"
     
  9. 90blzr

    90blzr 1/2 ton status

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    Where is exactly is the TPS? and how is it adusted?
     
  10. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    If I remember right, it's on the passenger side of the TBI unit. It can be adjusted by loosening the fastners and just moving it side to side. You pretty much need a multimeter or scanner for this. I've never done it myself, but I watched my instructor do it one day.

    "Liberals ain't mean, they just don't have any common sense!"
     
  11. mudpuppy89k5

    mudpuppy89k5 Registered Member

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    I had a problem with my '89 idling high. It was a little different in that it did it all the time. Turns out the gasket under the TBI was leaking. Replaced it and it has been fine ever since.

    John Perry
    http://www.mudpuppy.coloradok5.com/
     
  12. Pure Insanity

    Pure Insanity 1/2 ton status

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    yes the bracket that the throttle and tv(tranny)cables clip into.it should be spaced up also to align them back the way they were in relation to the t/b.this will also take care of the shifting problem,because w/ the t/b lifted you have essentially made the distance to the t/b to the cable mount longer and the tranny thinks that you have the truck to the floor.tv means throttle valve cable.it reads the position of the t/b butterflies to determine how to shift.it is adjustable BTW.(this is why i hate computerized vehicles!)altho i think the 700 has a tv cable w/out a computer also.i might be wrong tho.(if i am wrong dont tell anyone!)LOL!

    PURE INSANITY
    86 blazer see it at:<A target="_blank" HREF=http://www.zing.com/album/pictures.html?id=4292792569>http://www.zing.com/album/pictures.html?id=4292792569</A>
     
  13. 90K5

    90K5 1/2 ton status

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    If you just put the spacer on it, did you add another gasket? One on top and one on bottom.

    90K5

    See my truck at <A target="_blank" HREF=http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502>http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502</A>
     
  14. newyorkin

    newyorkin 1 ton status

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    90blzr, the shift is related to the TV cable, definately, as Pure Insanity said. You should space it equal to the TBI, since it's pain in the butt to adjust (although in your case, there must be a formula to determine the amount to adjust the cable comparable to it's new angle...). I would just space it equally, so your throttle and tv cable go back to their original positions together. Heck, maybe that'll cure the idle problem too, but I'm leaning with the gasket for that.
    The adjuster for the cable is a D-shaped brass/copper button recessed into the side of the plastic end of the cable jacket that snaps into the intake bracket. Push the button, and you can slide the cable jacket backward and forward (it may be real stiff at first from heat and age, so give it some elbow grease). Just envision it as you read that sentence, and you'll probably know it right away. I'll run out in a few and see if I can get a decent picture of one for you.

    Ratch
    **<A target="_blank" HREF=http://k5.8m.com>http://k5.8m.com</A> What more is there to life?**
     
  15. K5 NUTT

    K5 NUTT 1/2 ton status

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    Had the same problem 2 weeks ago after i finished my TBI swap....had to reset the min air setting....drill out the soft plug and adjust the screw untill she's back to normal. Spacer adds more airflow and the IAC can't compensate for it. Just drove from Phx to Co thru Utah to vegas and home...over 2K miles..no problems....my 2 cents.

    Azblazer

    1979 K5 350 TBI
    1976 K5 Chalet
    If it ain't got arizona pinstriping.....you ain't wheelin the pee outa her!
     
  16. 90blzr

    90blzr 1/2 ton status

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    Yes' there is a gasket on top and bottom. So to put the cables back so they are the same angle as they were before the spacer I need a 1" spacer under them since the TBI spacer is 1" right? Thanks for all the help. I'll try the spacer under the cables first because I know thats when the "weird" shifting started and who know maybe that has something to do with the idleing problem. I'll also make sure that the bolts holding down the TBI are still tight and if that still doesnt help I'll replace the gaskets. Thanks everyone and I'll let you all know how it turns out. All the help I need just a click away!!! This place is great! Who needs a service center when you've got CK5!!! LOL!!
     
  17. 90blzr

    90blzr 1/2 ton status

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    Ok, I just went out to put a spacer under the bracket for the cables. I cant. There is something (dont know what it is called) mounted on the firewall about 1/4" above it and will not allow the bracket to be moved up any farther. The part on the firewall has a rubber piece that 'squishes'in when you push on it and the cable with the long slot in it that is the closest to the d-side fender goes into it. No what I'm talking about? So I looked for the brass button on the tranny cable to adjust it that way, still cant find that. Maybe I'm just blind, but are these on all models for adjustment? The idling problem. Sprayed carb cleaner around the throttle body spacer and the idle remains the same, so I am assuming the gaskets are fine. All the bolts were tight. It was idling around 600 in the driveway when I started it up right now which it always does, but after I drive it for a while I notice when slowing down or parking, it wont come back down to that, almost like the choke is on . So now what??
     
  18. newyorkin

    newyorkin 1 ton status

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    90blzr, I'm not sure what the heck you have up there that squishes! I put up a bunch of pictures of the adjuster, one is on a 700r4 in my back yard, the other is in the truck. http://k5.8m.com What more is there to life?**<P ID="edit"><FONT SIZE=-1>Edited by newyorkin on 06/02/01 03:21 PM (server time).</FONT></P>
     
  19. 90blzr

    90blzr 1/2 ton status

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    Hey thanks 'newyorkin'!! I'll go try it. And the "squishy thing" isnt on your truck. On your pic of the TV cable in the truck, do you see the hex shaped arm coming out of the TB where the other cables hook onto, the cable coming out of 'the squishy thing' is hooked onto that on mine. Man I wish I knew what that thing was called!! So should I just pull it out an inch since thats how much I raised it up? I give it a shot.
     
  20. newyorkin

    newyorkin 1 ton status

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    No Problem!! Any excuse to be under the hood with the camera...
    I wouldn't move it a whole inch, remember, it's now angled upward, not moved backward. I'm sure there's a way to figure out exactly how much to adjust, cause this thing seriously effects shift. Try this: pop it off the throttle, hold it where it used to mount, put a clip on the cable exactly where the jacket starts covering the cable, then reconnect it to the throttle, and adjust the jacket out to where the clip now is. It's late, so that may make perfect sense in my head, and none in writing...
    Do you have cruise control? I can't remember for squat where that connects to TBI, if it uses the pedal cable or another one, coming from a diaphragm. Is the squishy thing (that's starting to sound kinda funny) a diaphram with a vaccuum hose on it, or some connection to a unit on your driver's side inner fender? Can you actuate it by 'squishing' it?? I can't think of anything else that would need throttle control. It's mounted on the firewall or further back on the manifold?? Firewall mount sounds odd, since then it would pull the cable if your motor moved...

    Good luck!! And no, you didn't just blow the tranny, it's really the cable!

    Ratch
    **<A target="_blank" HREF=http://k5.8m.com>http://k5.8m.com</A> What more is there to life?**
     

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