Fuel Pump Eccentric Problems

Discussion in '1965 - 1973 Classic Mustangs -General/Talk-' started by TexasJeff, May 29, 2014.

  1. Hello

    I have a 289 in a 66 coupe and the previous owners built the motor and I think did a few things wrong. First the bolt to the fuel pump eccentric came loose and the little tit of the eccentric that went into the cam broke off. Also I believe that this is a 2 piece eccentric and they only installed the one piece. I did not know better at the time and bought a new and replaced it as it was and have the second piece on shelf. What will happen with not having both pieces on there. I seem to loose fuel pressure from time to time. I am not sure what is right and wrong in this department. Any help is greatly appreciated.
  2. Built a '73 302 which I raced on the oval track (street stock division) from '88 through '92, then it went unaltered into my cousin in law's '81 Mustang. it originally had the 2 piece eccentric. I rebuilt it with only the 1 piece. Never had any trouble with it.
    Bought a '66 Mustang from a Utah farm in '01. It would run out of fuel pressure randomly. Replaced the fuel tank and sender. No more troubles.
  3. 289s have a one piece eccentric ,302s have a two piece eccentric ,I believe this started in 69. the wrong one in the wrong motor will hit the inside of the timing cover and wear a spot in it and put metal in your oil pan.the two piece eccentric has a nub on the back of it that locks into the cam gear so the pin does not come all the way through . If the pin is broken off in the cam and the bolt was loose ,the eccentric had to be spinning and not working the fuel pump. sounds like maybe the wrong pin was used for the one piece eccentric that should be in your 66 389, that one should protrude through the cam gear and into the one piece eccentric.