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TPI??? Speed sensor???

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Tommy, Jan 21, 2001.

  1. Tommy

    Tommy 1/2 ton status

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    What effect will not having speed sensor make on TPI? If desparately needed, what is the easiest solution for 70K5?

    Drive it Like You Hate It!
     
  2. BobK

    BobK 1/2 ton status

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    I believe there is an adapter you can get.I take it you have a TH350 right?Here's a link for you.
    <A target="_blank" HREF=http://www.jimsperformance.com/carty.html>http://www.jimsperformance.com/carty.html</A>
    It's the TPI speed generator.I got a TPI unit from this guy and he's real good to deal with.

    [​IMG]<font color=green>BobK<font color=green>
     
  3. BobK

    BobK 1/2 ton status

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    I believe there is an adapter you can get.I take it you have a TH350 right?Here's a link for you.
    <A target="_blank" HREF=http://www.jimsperformance.com/carty.html>http://www.jimsperformance.com/carty.html</A>
    It's the TPI speed generator.I put a TPI unit in my 71 Blazer.I got it from this guy and he's real good to deal with.His name is Jim.

    [​IMG]<font color=green>BobK<font color=green>
     
  4. Blazer79

    Blazer79 1/2 ton status

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    I think you can have a custom chip burned for you that doesn't require all the emissions stuff and the speed sensor.

    <font color=blue>//////
    <A target="_blank" HREF=http://blazer79.coloradok5.com>http://blazer79.coloradok5.com</A>
    </font color=blue>[​IMG]
     
  5. blazer72

    blazer72 1/2 ton status

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    the speed sensor is what tell the ECM that your not parked and its time to work not just sit there. The Painless wiring kit does not use it but says you can if you want. VDO make a sensor for the speedo that will work on the GM speedo out put and still let you have the stock speedo. I would use it as it will make the ECM think the truck goind down the High Way when it going down a trail. The VDO sensor can be had from summit for about 50 bucks

    I understand the jeep thing I drive a BLAZER!!

    Ken
     
  6. HarryH3

    HarryH3 1 ton status Author

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    Without the vehicle speed sensor (VSS) input, the ECM will set an error code, turn on the "Check Engine" light and go into "Limp Home" mode. This makes it ignore the input from the oxygen sensor and run in open loop mode. You get a bit less power and mileage since the ECM isn't continuously tuning the engine for best performance. The VSS can be programmed out with a custom chip, but the sensor that adapts to the speedo cable costs less.

    Here in Colorado, the check engine light MUST come on during key-on lamp test and it must go off when the engine is running. If not, you don't get an emissions sticker. [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
     
  7. BurbinOR

    BurbinOR 3/4 ton status

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    We programmed the VSS out with my custom chip............less to worry about and simpler.

    <font color=orange>'79 - 406 TPI -<font color=orange> K5#5 - <font color=blue>See it at---&gt;<A target="_blank" HREF=http://www.blazzinor.coloradok5.com>http://www.blazzinor.coloradok5.com</A>
     
  8. realsquash

    realsquash 1/2 ton status

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    On a TPI system (90-92 with a 1227730 ECM), the VSS is only used for "driveability" things, such as a high idle when coasting up to a stop sign, things like that. It is also used for top-speed limitation, but that wasn't enabled. If you don't have it, it won't set a code on the ECM.. It is worth buying one and running the 2 wires if you don't already have them. I've run mine both ways. It won't go into limp-home mode, either...

    Also, I bought my VSS from TPIS. It screws onto the NP205 where the speedo cable goes, then the cable goes on the VSS.

    Squash
    <A target="_blank" HREF=http://www.trailrunners4x4.org/users/realsquash>http://www.trailrunners4x4.org/users/realsquash</A>
     
  9. HarryH3

    HarryH3 1 ton status Author

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    GM musta changed something in the later years. My '87 'vette TPI sets a VSS code within a half mile if the VSS isn't connected. [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
     
  10. realsquash

    realsquash 1/2 ton status

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    Yep, they musta because the 87-89 were MAF, 1227165 ECMs (which is a C3). And 86 was something goofy, I seem to remember a hand-crank behind the glovebox. The 1227730 is a P4 and is MAP on the 90-92 f-body's.

    Squash
    <A target="_blank" HREF=http://www.trailrunners4x4.org/users/realsquash>http://www.trailrunners4x4.org/users/realsquash</A>
     

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