1968 Ford Mustang Problems. Any ideas?

Okay I have a 1968 Ford Mustang.When I accelerate,after I have been driving for a while my car begins to jerk if I don't feather the acceleration,also if I try to accelerate between 65 75 the car will either jerk or just not go any farther.I know that it's not that i have a chip in my car to prevent me from accelerating to high speeds because my dad did that with the car when my sister had it when she turned 16 and she had it removed when she turned 18,and my dad never did it for me

I know that it's not:


fuel pump-replaced.


something in the tank-drained the gass and pulled the tank-I also cleaned the sock filter.

the resister wire-i set up an external one.

I know there's not a problem with the carb-I had a mechanic rebuild it.

The gass cap vent-I drove with it off.

replaced the fule filter at the carb.

Do you have any ideas?

13 Answers

  • 1 decade ago
    Favorite Answer

    It prob is your valve springs, if that is not the problem it could also be the floats on the carb. I would put new valve springs in to see if there is a difference

  • Anonymous
    5 years ago

    Google Ford Mustang. It is common for old Mustangs to leak at the windshield and rear window. If youdo not find and fix the leak soon, the car will grow mold on the inside and stink! There are a lot of old car aftermarket parts out there. Try e-bay or Hemmings motor news. You could also buy a mustang or street rod magazine and go through the adds. Good Luck

  • 1 decade ago

    your car has no chip, if someone put something to reduce acceleration have it removed ,you may need the power to get out of a accident, if you need to feather it its a carburetor , need to know what in the world did someone do to prevent this speeding thing ? its dumb and unsafe and dumb, and stop changing parts ! if you don't know what's wrong have it properly diagnosed , you cannot fix it just changing stuff, and see where your at now , so take it to some one who know cars and have it diagnosed, it you know all this than it would be fine but its not so start over, take care

    Source(s): 26 year car & truck mechanic
  • 1 decade ago

    Awesome....used to have a 68 coupe!!!!! If it is after you drive it for a while then it is possible its vapor locking??? the fuel line on these usualy ran right up the right side front of the cylider (HOT!!!!)....I lived in death valley when i had mine and re routed the fuel line away from the heat and (sounds stupid) threw a few clothes pins on the fuel line and never had another problem....the clothespins will help to dispate the heat from the line.

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  • 1 decade ago

    Have you had the Carb rebuilt recently? It maybe the accelerator pump on it going bad. Or the floats are sticking and such. Is hard to say.

  • 1 decade ago

    sounds like you've tried everything but pulling the exhaust. I'd do that and then blow the gas line. You've got a restriction somewhere happy hunting. How do you put a speed restriction on a 68? We used to have governors on some big blocks that acted like a cruise control- just hold the petal to the metal and 45 was all you got. strange.

    Source(s): owned a 68 mustang. mech since eary 60's
  • 1 decade ago

    These old cars were known to have a dead spot in their carberators after they have alot of miles..

    Change the carb.

    Alot of times it's the butterfly rod that wares out and causes the carb to suck in more air,, there is no fix except changing the carb.

  • Anonymous
    1 decade ago

    How old are you and what are you doing trying to accelerate above 65 mph? Yea I know what is wrong and when you turn 21 and appreciate what your driving I'll tell ya

    Source(s): GM emp 31 yrs and an avid car enthusiast with friends who are the same
  • 1 decade ago

    if you replaced the carb then it would probibly be a linkage on the carb to long maybe?

  • Anonymous
    1 decade ago

    You have a flat spot on your distributor shaft. Or you timing has jumped a few notches.

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