Recent content by Scottm

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    99 L29 454 build

    Extreme, the pressure in the manifold is almost always less than ambient. The vacuum level is typically about 15 inches at idle to 24 inches when coasting down. (29 inches is absolute vacuum). The only time manifold pressure approaches atmospheric is at wot when air flows in with minimum...
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    99 L29 454 build

    Thanks Mang! (See what I did there?) That is so true about the intake. Go back to post 44 of this thread, where I drilled the manifold and put a thermocouple probe into the number 2 cylinder runner. Air going into the head was at the full temperature of the engine, 190+. More throttle didn't...
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    99 L29 454 build

    Ok thanks. That's great as long as it can do the obvious, which is reduce timing as engine load and cylinder pressure goes up. I trust they will get it right this time. If not, can I send it to you L31? I just thought of something. The egr is turned off in the tune. Could they be forgetting to...
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    99 L29 454 build

    I'm on something like the 8th trip back up to the tuner. Besides still pinging at wot, it audibly and steadily pings at hway speed 55-65 climbing slight hills, when rolling into the throttle in 3rd and 4th gear, and at 30-40% throttle accelerating through the gears. So I asked them to reduce wot...
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    Another 454 Vortec Build Thread - Documenting, Q&A, Help

    How's the compression? No sense worrying about injectors if it's not healthy.
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    Another 454 Vortec Build Thread - Documenting, Q&A, Help

    Ok I see, yes I was trying to say fuel tank pressure sensor, which is what I though OP was asking about.
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    Another 454 Vortec Build Thread - Documenting, Q&A, Help

    Here is the full page. FPS started in 98. And I don't know if this is relevant to what you were saying.
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    Another 454 Vortec Build Thread - Documenting, Q&A, Help

    Ok, I am trying to understand. You said this: I posted page from the 98 c/k service manual, showing the ftp circuit on the 7.4L engine, so it has to be a 2500/3500. Edit - I see the top of the page that said 7.4l was cut off, sorry.
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    Another 454 Vortec Build Thread - Documenting, Q&A, Help

    "Yeah, I'm going to have to go ahead and disagree with ya there..." 1998 c/k factory service manual:
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    Another 454 Vortec Build Thread - Documenting, Q&A, Help

    Super, I think they started using a fuel pressure sensor starting in 98. It was an option for me to wire in with the 0411 swap.
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    Another 454 Vortec Build Thread - Documenting, Q&A, Help

    Bex, how long should the stock rail and regulator hold pressure? My Holley aftermarket fpr bleeds down pretty fast, but I don't think it hurts anything, as it goes immediately to full pressure when I hit the key.
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    Another 454 Vortec Build Thread - Documenting, Q&A, Help

    How bad is the gas? I would siphon it all out.
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    6.5 to 454 vortec swap

    Isn't the pushbutton 4wd on 1/2 ton only?
  14. S

    6.5 to 454 vortec swap

    You will want to swap in the L29's complete wiring harness and ecm. It's completely different from the throttle body wiring. You should consider doing the 0411 ecm swap too. It's a lot of work, but worth it if you have the time. I found burned wires in a couple places on mine, that I never would...
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    6.5 to 454 vortec swap

    3/4T suburbans are cool, especially when they have the 14 bolt full floater axle. Maybe leave it alone and find another engine/trans.
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