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TPS voltage tuning

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Burbinator, Nov 5, 2001.

  1. Burbinator

    Burbinator 1/2 ton status

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    When I used to race EFI Mustangs years ago for a hobby, one little tweak we used to do was dial in the TPS sensor voltage at idle to about .90 - 1.0 VDC. Is there a similar tweak on the TBI? If so, what is the optimum voltage (idle) and which wire should the reading be taken from?

    Thanks in advance!

    The learning curve is a toll road...ride with someone who has already paid!
    <a target="_blank" href=http://photos.yahoo.com/abshort1>U.S.S. Nimitz II</a>
     
  2. tlarsw

    tlarsw 1/2 ton status

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    TPS voltage should be &lt;1.25 volts on the GM TBI.

    The three wires are (I'm color blind) black, grey and blue (I think)

    I think it's the grey and blue wires. You can make a jumper wire (NAPA has all the right connectors) and leave an offest bare spot on each wire. Check between two wires, If you get a reading of 5 volts, this is the reference wire. You'll check between the other two wires.

    1986 K10 TPI350/NV4500/Gen2 Doubler/D60(ARB)/14FF(Detroit)/4.56 gears
     
  3. Burbinator

    Burbinator 1/2 ton status

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    There should be a reference voltage (+5VDC), ground and the output voltage used by the computer. Sounds like the grey would be the output, blue for the reference and black for the ground.

    "&lt; 1.25 VDC" is good for verifying a good part, but there should be an "optimum", similar to the Mustang 5.0

    The learning curve is a toll road...ride with someone who has already paid!
    <a target="_blank" href=http://photos.yahoo.com/abshort1>U.S.S. Nimitz II</a>
     
  4. tlarsw

    tlarsw 1/2 ton status

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    That is correct on the TPI. (.52 +/- .075 VDC)

    I just set up a TBI this weekend using the GM fuel injection manual.

    For the TBI, it only stated that it had to be &lt; 1.25.

    I figured it's because the TBI doesn't have the performance characteristics of the TPI or 5.0 injection system.

    1986 K10 TPI350/NV4500/Gen2 Doubler/D60(ARB)/14FF(Detroit)/4.56 gears
     
  5. Burbinator

    Burbinator 1/2 ton status

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    Thanks for the info, but I'm not interested in what the manual says.

    I'm looking for the "field tweak". True, it doesn't have the performance characteristics of the other systems, but there should be a voltage that works better than most.

    The F*rd 5.0L manual said "&lt; 1.2 VDC", .90 VDC was optimal...see my point?

    The learning curve is a toll road...ride with someone who has already paid!
    <a target="_blank" href=http://photos.yahoo.com/abshort1>U.S.S. Nimitz II</a><P ID="edit"><FONT class="small">Edited by Burbinator on 11/05/01 03:37 PM.</FONT></P>
     
  6. Thunder

    Thunder 3/4 ton status

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    With a TBI you get better results tweaking the MAP sensor than the TPS.
    Summit sels some boxes for the TPS that will take care of the bog you somtimes get with a TBI
    But go to :http://coloradok5.com/gallery/Thunders-Blaze
    <font color=blue>NEVADA: Where the pavement ends, and the West begins.</font color=blue>
     
  7. Burbinator

    Burbinator 1/2 ton status

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    Now that's what I'm talking about!

    I knew there had to be SOMETHING to improve it...

    Thanks!

    The learning curve is a toll road...ride with someone who has already paid!
    <a target="_blank" href=http://photos.yahoo.com/abshort1>U.S.S. Nimitz II</a>
     
  8. Cavalry

    Cavalry 1/2 ton status

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    Not quite what you asked for but if you put a 640 ohm resistor across the coolant sensor the computer will think the engine isnt warmed up and give you more advance and hence power...

    "There is a fine line between hobby and mental illness"
    Luke
    84 K5
     
  9. K5 NUTT

    K5 NUTT 1/2 ton status

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    Remove TPS...hog out mounting holes...adjust to about .075V with scanner. Have scanner in the garage...can help you out some weekend.

    Azblazer

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

    Burbinator 1/2 ton status

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    I might take you up on that offer...thanks!

    The learning curve is a toll road...ride with someone who has already paid!
    <a target="_blank" href=http://photos.yahoo.com/abshort1>U.S.S. Nimitz II</a>
     

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