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What is the name of this part?

Discussion in 'Engine & Performance' started by FireTruck1984, Mar 24, 2020.

  1. FireTruck1984

    FireTruck1984 Full Access Member

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    789D3B8E-AAEB-48D3-AF0D-D0FDB0F15E94.jpeg What’s this called? Part of the smog equipment, sits on the front of the engine attached to the alternator bracket.

    6BEEDFDF-E50D-416F-8F86-13D9541C8435.jpeg
     
    Last edited: Mar 24, 2020
  2. Turbo4whl

    Turbo4whl Full Access Member

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    That is your decel (deceleration) valve. Should keep the engine from popping when letting off the throttle.
     
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  3. FireTruck1984

    FireTruck1984 Full Access Member

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    Thank you ! I’ll order a new one
     
  4. FireTruck1984

    FireTruck1984 Full Access Member

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    I’ve checked all the usual supplier sites for this Deceleration valve, no luck ! Any suggestions?
     
  5. Craig 85

    Craig 85 Full Access Member

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    Does it have any type of part number on it? I know I was able to find one for my truck once I found the GM or ACDelco number. Sorry mine is a different style. Mine had a part number on the bracket and the pod in the lower left. It let me do a search to find aftermarket replacement parts.

    Throttle lever actuator 2.jpg
     
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  6. FireTruck1984

    FireTruck1984 Full Access Member

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    Thanks Craig, no part # anywhere. It appears to be the original factory part. My local NAPA parts store should be able to track it down
     
  7. RecklessWOT

    RecklessWOT Full Access Member

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    Sometimes they're referred to as a throttle return dashpot, or just a carb dashpot. Even some older fuel injected vehicles have them. Though technically dashpots should be mechanical devices rather than vacuum. Still, you may have luck if you search that term
     
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  8. FireTruck1984

    FireTruck1984 Full Access Member

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    Thanks
     
  9. Turbo4whl

    Turbo4whl Full Access Member

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    The picture that @Craig 85 posted is a dash pot and it works differently to fix the same problem, engine popping on rapid throttle release.

    Here is the basic issue, when you let off the throttle fast from a higher RPM the vacuum in the intake spikes very high. No air past the throttle plates, but the engine (as we know a big air pump) pulling hard. So what happens, the fuel that has puddled in the intake floats up and fires off causing the popping.

    The dash pot method, holds the throttle so it will close slower, so no popping. The issue could be this dash pod will stick and cause wide open throttle.

    Better (or maybe only safer) is the decel valve that lets some filtered air enter the intake so the vacuum doesn't spike high.

    Many of the carburetor issues go away with fuel injection, but I still like carbs, I'm old school.
     
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  10. FireTruck1984

    FireTruck1984 Full Access Member

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    Good info, thanks. I accidentally broke off one of the fittings on this part, it’s the only reason I’m replacing it, everything was running fine before I broke it and
    Because of its age it snapped off easily. Now I just need to locate one
     
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  11. Big Chip

    Big Chip Full Access Member

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  12. FireTruck1984

    FireTruck1984 Full Access Member

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  13. SquareRoot

    SquareRoot Full Access Member

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    Edelbrock Pro-Flo. I promise you won't regret it. Buy once, cry once.
     
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  14. Craig 85

    Craig 85 Full Access Member

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    Looks like this could be an ACDelco replacement number 214-438. The GM number supercedes this part. Found one on Amazon, but I can't read the full description in the drop down menu. It has two 305's, but says it one fits one of them. Hopefully they actually have it in stock. About $27 with free shipping. From what I can tell, there are no other manufacturers for this part.

    https://www.wholesalegmpartsonline....ntrol-System-AIR-Valves/2681979/14034026.html

    https://www.amazon.com/ACDelco-214-438-Deceleration-Valve-Diaphragm/dp/B000C9K1YO/ref=au_as_r?_encoding=UTF8&Make=Chevrolet|47&Model=G10|446&Year=1984|1984&ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=2&vehicleType=automotive
     
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  15. FireTruck1984

    FireTruck1984 Full Access Member

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    Thank you sir, you’re a gentleman and a true patriot
     
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