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  1. #1

    Default Dashpot kicking idle up about 500 rpm

    Hi All,
    I don't do much in the way of forums or other social media, so I'm new here and I need your help please.
    My mechanic fixed vacuum issues on my 85 GT that were due to bad gaskets at the carb/EGR/intake.
    Prior to this repair, he rebuilt my carb with a Motorcraft NOS correct kit and replaced my original A/C dashpot
    that wasn't working. I spent the big bucks at a restoration site to get an NOS unit since there are no longer any
    others available. It operated fine prior to fixing the gaskets/vacuum issue.
    But he's now telling me that all is fine except that the dashpot is now kicking the idle up by 500 rpm or so,
    which is way too high.
    Any ideas on what may be going on?

    1985 GT, 5 speed, 27500 original miles and the drivetrain is all stock.
    Only real mod is the exhaust. BBK catted H-pipe and Flowmaster Series 50 mufflers w/2.5" tailpipes

    Thanks!
    Last edited by 85Pony; 08-24-2020 at 06:43 PM.

  2. #2
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    qikgts's Avatar
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    Default

    Sounds like you've got a overly strong throttle kicker. I've never heard of one picking up 500 rpm. If I recall correctly you should see about 100-150 rpm.

    What p/n did you get? Mr. Cook (if you spend enough time here you'll know who he is) posted these p/n's some time ago as being suitable. E3PZ-9S520-A, E4PZ-9S520-A, Motorcraft CD-78, Standard ES-72 or Wells 3H1069
    '85 GT

  3. #3

    Default

    You should be able to back it off I would think. Is there an adjustment on the base of the pot or the part if the throttle it hits?
    1984.5 G.T.350 5.0 CFI AOD Convertible (TRX package, loaded)
    K&N filter in a stock dual snorkel, GT40 heads, Edelbrock 3721 intake, MSD 8456 Dist., MSD 8227 coil
    Comp cams XE254H, hypereutectic pistons
    Hooker Super Comp Shorty Equal Length Headers, catted BBK H-pipe, full custom duals
    Maximum Motorsports caster/camber plates and strut tower brace, 3.73 rear, dura grip (both Yukon)
    Ford Performance Springs, Firehawk A/S 225/55r16 on LMR TRX r390 wheels (street)
    Federal 595 rs-rr 245/40r17 and 255/40r17 on OE cobra r wheels (race)
    AOD rebuilt with a 6 clutch direct drum, Koline steels stacked with 8 clutches, Kevlar band, superior shift kit, new torque converter. --Everything else stock and fully functional.

  4. #4

    Default

    Tahnks to both of you for your replies.
    I bought this from Fox Mustang Resto. and they didn't indicate a p/n but said it is an NOS unit. So I would think that's Motorcraft.
    It came in a non-descript sealed plastic bag and looks like the original.
    I didn't see any type of adjustment on it and my mechanic says he couldn't find one.
    It was working fine and only holding the idle up by about 150 to 200 rpm prior to fixing the leaky carb base gaskets.
    I know him well and if he tells me all he did was disconnect it, replace the gaskets and then reconnect it, that's all he did,
    unless it's something he isn't aware of doing. So we are both at a loss.

    I just took another look at my receipt and there is a PB8 noted on it. I'm not familiar with that p/n.
    Last edited by 85Pony; 08-24-2020 at 08:33 PM.

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