engine stalling

  • Help,I can't seem to get the engine to run correctly at lower rpm. At mid range an above car seems to respond fine runs good, but at idle and when coming off of a light it stalls, runs rough, have to baby throttle or put in neutral to keep going. It also seems to get worse as it gets hotter or runs longer. carb is fairly new from pony, I changed dual points an cond. replaced hose to pcv with clamps.what could it be?

  • A not-uncommon leak is the carb to manifold, especially if you have an aluminum highrise under the carb. If you do, there is a spacer for a Ford truck that is the right thickness for your application. Good luck!!<img src=images/icon_smile_big.gif border=0 align=middle>

  • no highrise, just a spacer for the pcv hose. gaskets seem fine, 4 nuts on carb are tight. replaced hose an clamps on base to valve. seems to idle ok with trans in park or neutral but when I put it in gear it will get rough an stall.

  • How about the rubber vacuum line connections from hard line from manifold to tranny? Any cracks or breaks, especially at the modulator valve on the tranny? You can use a propane torch (small hand held type) with a piece of rubber tubing as an extension, turn on the propane (without lighting it) and run the hose end around the manifolds (with engine running), & carb gaskets, ect and the engine will usually idle up higher when you get to an area of a vacuum leak.


    Edited by - 66tiger on 06/01/2008 22:49:44

  • I sprayed around carb an fittings while engine was running an there was no noticable change, I have read many threads about coil, could the coil be causing this at lower rpm an not at high? my coil is a yellow cap from npd. I did not think a bad coil would run fine at higher rpm's.

  • Don't think it's the coil as they normally show

    their bad side on high rpm's. Too me this problem

    sounds like a carb that has an issue between the

    idle and main system when you press the gas pedal.

    Does it react at all on the idle mixture screws?

    If not, it can be a faulty or wrong power valve or flaps that

    aren't adjusted correctly. In my opinion though,

    I think the most likely issue is the float adjustments.

    Pony rebuilt my 3259 Holley for my 65 Shelby many

    years ago and it ran like a bear with the symptoms

    you describe. It was two major issues, float levels

    were wrongly adjusted and the power valve had the incorrect

    opening value. After I corrected the two issues it ran excellent.

    /Bo

  • Float level adjustment figures are specified in

    the 66 Shop Manual. However, I couldn't find any data

    for a 66 Auto HiPo C6ZF-F. Another thing, have you checked

    the advance curve on your distributor?

    /Bo

    • Official Post

    According to the spec sheet in a Ford carburetor kit the floats are 1/2" on the primary and 5/8" on the secondary.

    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

    • Official Post

    The Ford carburetor kit comes with detailed instructions and a gauge for measuring the setting. The carb kit number is a C2SZ 9A586 D. The measurement is taken at 1/8" from the toe of the float.

    -Fred-

    65 Koupe early San Jose Phoenician Yellow 4 speed
    66 GT Koupe Dearborn Blue 4 speed
    66 KGT San Jose fastback pony interior Silver Frost 4 speed
    64 Falcon sedan delivery 289 4 speed
    65 Ranchero 289 4 speed
    66 Corvette roadster 427/425 4 speed

  • After talking with pony carb, they strongly suggested not to touch carb. they also said that because of the reengineering inside the carb that the settings are not the same as the ford specs. so I searched elsewhere an after getting a coil from jdlarson, installed today an problem gone, runs great, I guess coils can be bad at low rpm an not high. At least the china knockoffs anyway. Thanks to everyone that had input.

Participate now!

Don’t have an account yet? Register yourself now and be a part of our community!