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  •  » Idle Rpm

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    1/27/2022 3:51 PM  #1

    Toploader
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    Registered: 4/15/2013
    Posts: 1,640

    Idle Rpm

    I cannot seem to get my engine to idle any lower than about 850-900 rpm. I have the timing set to about 14 degrees as that seems to be where it likes it. The air/fuel mixtures are pretty good too, because if I turn them in a quarter turn, the engine starts to idle rough.
    Engine runs great and the idle doesn't seem bad. I just wondered why the idle won't come down any more.
    What do you guys have the idle set at?

    1964-1/2 D Code Coupe - 289 V8, 4 Speed Toploader, 3.00 ratio rear, Autolite 4100 Carb, 15" tires, Pertronix ignition
     

    1/27/2022 4:09 PM  #2

    lowercasesteve
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    From: Auburn, Ca
    Registered: 4/01/2013
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    Re: Idle Rpm

    Don't worry about it.  mine idles at 800-900 rpm.  And the '15GT idles at 800.  There is nothing special about 600-700.

    Original owner - 351w,T-5, 4whl disks, power R&P
     

    1/27/2022 4:58 PM  #3

    6sally6
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    From: Surfside Beach,SC
    Registered: 4/02/2013
    Posts: 6,852

    Re: Idle Rpm

    As you know...the more initial advance...the higher it idles....until you turn the curb idle down!
    Ensure the linkage is not binding....not stuck on the carpet (don't laugh!)....choke open all the way....check it when engine is hot.

    No snotty idle camshaft. right?
    SURE there is NO vacuum leak?
    Can you choke it down by covering the top of the carb with your hand?
    4 speed NOT an A/T right?!
    What happens IF....you take out some of the initial?

    Steve's right really....nut'in worng with  850-900 RPM.

    Try ^^^ this stuff and let us know!
    6sally6

    Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
     

    1/27/2022 5:13 PM  #4

    Rudi
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    From: Stuck in the 50's Welland Ca
    Registered: 4/01/2013
    Posts: 3,974

    Re: Idle Rpm

    My 331, Holley 670, Crane optical diz and control box, AOD idles at 750-800 in drive air on, 900in neutral.
    It also does not like any lower rpm
    At first glance I thought the post was referring to BB2 being slothful but I couldn’t imagine that scenario 😱

    Good work ain't cheap, Cheap work ain't good!   Simple Man
     

    1/27/2022 7:56 PM  #5

    MS
    Forum Originator

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    From: Canyon Lake, Texas
    Registered: 1/24/2013
    Posts: 12,253

    Re: Idle Rpm

    What cam specs?

    Money you enjoy wasting is NOT wasted money... unless your wife finds out.
     

    1/28/2022 5:22 AM  #6

    Toploader
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    Re: Idle Rpm

    lowercasesteve wrote:

    Don't worry about it.  mine idles at 800-900 rpm.  And the '15GT idles at 800.  There is nothing special about 600-700.

    Fair enough... that is good to know.

    1964-1/2 D Code Coupe - 289 V8, 4 Speed Toploader, 3.00 ratio rear, Autolite 4100 Carb, 15" tires, Pertronix ignition
       •Thread Starter
     

    1/28/2022 5:24 AM  #7

    Toploader
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    Re: Idle Rpm

    MS wrote:

    What cam specs?

    I'm not sure of the specs. I rebuilt the engine in about 2005 and only remember telling the shop that I wanted torque and economy with the grind.
    Its not a wild cam or anything...

    1964-1/2 D Code Coupe - 289 V8, 4 Speed Toploader, 3.00 ratio rear, Autolite 4100 Carb, 15" tires, Pertronix ignition
       •Thread Starter
     

    1/28/2022 5:31 AM  #8

    Toploader
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    Re: Idle Rpm

    6sally6 wrote:

    As you know...the more initial advance...the higher it idles....until you turn the curb idle down!
    Ensure the linkage is not binding....not stuck on the carpet (don't laugh!)....choke open all the way....check it when engine is hot.

    No snotty idle camshaft. right?
    SURE there is NO vacuum leak?
    Can you choke it down by covering the top of the carb with your hand?
    4 speed NOT an A/T right?!
    What happens IF....you take out some of the initial?

    Steve's right really....nut'in worng with  850-900 RPM.

    Try ^^^ this stuff and let us know!
    6sally6

     
    So maybe it's to do with how much advance I have? It likes 14 degrees, so I will live with it. If I backed off timing, the rpm would lower.
    I will check the throttle linkage to make certain there's no binding on carpet.
    Everything else seems ok. Choke fully open. The idle screw on the throttle linkage is mostly undone.

    1964-1/2 D Code Coupe - 289 V8, 4 Speed Toploader, 3.00 ratio rear, Autolite 4100 Carb, 15" tires, Pertronix ignition
       •Thread Starter
     

    1/28/2022 5:45 AM  #9

    TKOPerformance
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    From: Newark, DE
    Registered: 12/15/2014
    Posts: 7,498

    Re: Idle Rpm

    Once you deviate from stock in any way you can no longer go by stock settings for things like idle speed.  My internally stock A code 289 idles at 750-800RPM.  500cfm Edelbrock, Edelbrock Performer intake, JBA headers and 2.5" Magnaflow exhaust, electric fan, Pertronic coil & Ignitor, and initial timing set at 12 degrees with 26 degrees mechanical advance & lightest springs.  Runs like a scalded dog for what it is though. 

     

    1/28/2022 6:22 AM  #10

    Nos681
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    From: Atlantic Mine, Michigan
    Registered: 7/14/2016
    Posts: 3,331

    Re: Idle Rpm

    Rudi wrote:

    At first glance I thought the post was referring to BB2 being slothful but I couldn’t imagine that scenario 😱

     

    I couldn’t image that either.😁

     

    1/28/2022 10:46 AM  #11

    6sally6
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    From: Surfside Beach,SC
    Registered: 4/02/2013
    Posts: 6,852

    Re: Idle Rpm

    Double check that a vacuum leak has not occurred.
    MAKE SURE the secondaries are not cracked open just a dab.
    IF the curb idle screw is totally backed off and the idle doesn't drop off......well "I THINK" sump'in ain't right.
    I know all carbs are a little different  butt-awl I've seen will drop the idle to ZERO if the screw is backed-off totally.
    Maybe disconnect the linkage and see what happens.
    Eliminate stuff one-step-at-a-time.
    Linkage
    Vacuum leak
    Open secondary blades
    Throttle bushings worn
    Does it have a lopey idle?!  OR Smooth?

    Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
     

    1/28/2022 11:04 AM  #12

    rpm
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    From: Bakersfield, Ca
    Registered: 9/17/2013
    Posts: 3,654

    Re: Idle Rpm

    Rudi wrote:

    At first glance I thought the post was referring to BB2 being slothful but I couldn’t imagine that scenario 😱

    I'm king of the sloths. I can sit around and do nothing, and I do it pretty well. Fred Sanford's got nuttin on me.

    Bob. 69 Mach 1, 393W, SMOD Toploader, Armstrong  steering, factory AC.
     

    1/28/2022 11:38 AM  #13

    Rudi
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    From: Stuck in the 50's Welland Ca
    Registered: 4/01/2013
    Posts: 3,974

    Re: Idle Rpm

    Bearing Bob wrote:

    Rudi wrote:

    At first glance I thought the post was referring to BB2 being slothful but I couldn’t imagine that scenario 😱

    I'm king of the sloths. I can sit around and do nothing, and I do it pretty well. Fred Sanford's got nuttin on me.

     
    Ah hah, I to am a long standing card carrying “Guardian of the recliner “ member!
    With the wuhan virus and cold weather here I have become a mañana kind of guy.

    Good work ain't cheap, Cheap work ain't good!   Simple Man
     

     

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