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Fuel pressure for TBI

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Truckfan2, Apr 18, 2000.

  1. Truckfan2

    Truckfan2 1/2 ton status

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    I have a stock TBI on my truck with a Compcam but I am also planning on puting on the Holley 670 cfm TBI unit and their intake manifold and vortec heads. How would I bump up the fuel pressure on my system? Anyboby know? thanks for the help!

    NEVER been stuck... *yet*
     
  2. Brian 89KBlazer

    Brian 89KBlazer 1/2 ton status

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    JET (www.jet-chip.com), Turbo City (www.turbocity.com), Summit Racing (summitracing.com), and Howell Fuel Injection (www.howell-efi.com) are just a few of the many companies that can sell you an adjustable fuel pressure regulator. Most can also answer any other questions you may have about anything TBI.

    Good Luck
    Brian
    Still in search of the TBI KING!!
     
  3. Truckfan2

    Truckfan2 1/2 ton status

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    where does the regulator install and isn't the amount of fuel let into the engine controlled by the computer???

    NEVER been stuck... *yet*
     
  4. Brian 89KBlazer

    Brian 89KBlazer 1/2 ton status

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    The regulator unit is in the back center part of the throttle body unit (right between the two injectors) and yes the computer controls the fuel flow but if the computer says more fuel and there's not enough there, then "Houston, we have a problem"!! The engine will stumble without enough gas.

    Hope this helps
    Brian
    Still in search of the TBI KING!!
     
  5. Truckfan2

    Truckfan2 1/2 ton status

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    that explains it... thank you very much!! I needed that! Later~Pete

    NEVER been stuck... *yet*
     
  6. SnakeEyes

    SnakeEyes Registered Member

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    The fuel regulator can only allow as much pressure to the TBI as the pump can supply. If my memory serves me well, the TBI uses only 8-10psig. The pump probably can supply only up to about 15psig. Is this enough for your purposes???
     
  7. Truckfan2

    Truckfan2 1/2 ton status

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    I dunno quite yet, i'm waiting to sell some parts and buy the Holley 670 cfm TBI unit and intake and get some vortec heads... what do you think about the combo?? oh yeah, I got a CompCam for a TBI engine in now and also a 4x4 Cam that I'm going to try.

    NEVER been stuck... *yet*
     
  8. Bigd

    Bigd 1/2 ton status

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    The deal with higher fuel pressure and increasing horsepower on fuel injected motors.Is that the computer tells the injector to open and when and how long sometimes.The higher pressure will introduce the fuel slightly faster and more of it.I say slightly because the injector will only flow so much fuel thats why there rated like 36 pounds/hour.I believe that the holley kit comes with a higher rated injector to combine with its larger throtle body.And also a to high of pressure will destroy injector seals.What does holley recommend for it's tbi.I know its almost a sin but learned alot from working on a fuel injected mustang.
     
  9. Truckfan2

    Truckfan2 1/2 ton status

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    stock PPH is 36??? i just looked at Holley's specs for their TBI and it is 64 PPH and Hi-Flow is 69 PPH... could stock really be that low at 36 PPH? Anyone now the exact rated PPH the injectors on the stock TBI? Thanks for the great info!

    NEVER been stuck... *yet*
     
  10. Bigd

    Bigd 1/2 ton status

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    Sorry was just using that number as an example.Not sure what the stock numbers where.
     

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