Found Vacuum leaks, and replaced leaky Accelerator pump.. But..

Discussion in 'Ranchero Tech Help' started by Rancherestorer19, May 7, 2014.

  1. Rancherestorer19

    Rancherestorer19 In Fourth Gear

    Messages:
    271
    Location:
    McPherson Kansas
    it's not a major problem, it runs and it idles very nicely.. but I replaced the Accelerator pump and I found a really big vacuum leak and fixed it. and now at 500ROM in Gear it runs very very nicely, no shakes at all, but there is a new problem which has developed after readjusting the Fuel/Air ratio.

    Now whenever I push the accelerator it cuts out. It cuts out then revs and runs great. just that cut out when I first hit the accelerator. It is like it hesitates, then runs fine. This is a Holley 2 Barrel that came original with the vehicle, no idea what the number or CFM anything like that are or where to find them..

    Does anyone else have any ideas as to what could be causing this? it is definitely a carburetor issue i my opinion, but what???

    I am going to look through my repair manual.. it is almost acting like it is flooding when I step on it.. it did not do this until I replaced the accelerator pump and fixed the vacuum leaks and adjusted fuel/air ratio. This is strange to me.. That vacuum leak has been there ever since I bought this Ranchero.. it's good to hear it running smoothly at Idle for the first time since I bought it, but now I have no power because it cuts out like this.. and it makes a strange quick high pitched burping sound when I throttle it, kinda sounds like a duck, then stumbles, then idles up, the sound comes from inside the butterfly valve in the top. before when I would goose it like that it would make a very loud Hiss. Something is wrong here I am pulling my Repair Manual, but I am trying to diagnose this.. need some help please..
     
  2. bscottie

    bscottie In Maximum Overdrive GOLD MEMBER

    sounds like your accelerator pump needs a final adjustment
     
  3. Huevos

    Huevos In Maximum Overdrive

    Messages:
    3,434
    Location:
    Nor Cal
    I always find a couple of cartoon characters can help me with a accelerator pump problem...
     
    Kane likes this.
  4. Rancherestorer19

    Rancherestorer19 In Fourth Gear

    Messages:
    271
    Location:
    McPherson Kansas
    I've said it before and I will say it again.. you guys are awesome!! Thank you so much, that cartoon helped me a lot!! I will definitely check it out.. sounds like maybe it is not getting enough fuel when I pump it, an adjustment is necessary thus the cut out..
     
  5. Kane

    Kane In First Gear

    Messages:
    7
    Location:
    Sothern California
    this is awesome!
     
  6. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    12,133
    Location:
    Seguin, TX
    I noticed you have the idle at 500 RPM; IIRC, idle speed for an auto (I'm assuming an auto trans) is supposed to be 600 +/- 50 RPM. Could that flat spot be from the throttle not stroking the accelerator pump? I' d rather have the idle set correctly without an accel pump adjustment than a lower idle with an accel pump adjustment.
     
  7. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    12,133
    Location:
    Seguin, TX
    I noticed your rig has a 351W/C4; I dropped the same combo in mine to replace the seized 351M/FMX boat anchor. With a factory-type carb (Motorcraft 2150 from a '75 351W), I have mine set as I suggested above, although I need to do a finishing dial-in on idle mixture and timing, which is coming later. I have no problems with the engine 'pulling' the car along against the brakes.
     

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