Non camaro, tuning headache

Discussion in 'Troubleshooting & Diagnosis' started by jroach, Jan 8, 2021.

  1. jroach

    jroach Veteran Member

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    I apologize for the long post.
    So I'm having some issues with my 1978 chrysler Newport. its a 400 bmotor 727 trans. I have deleted the electronic lean burn system with an after market ignition based on the 72 mopar standard electronic ignition. I have replaced the factory thermoquad with a gm quadrajet. I am running light weight springs in the distributor and I currently have the vacuum advance hooked up to a ported source currently. I seem to be unable to read the balancer with a timing light. The initial timing was set by trial and error. Basically had it retarded and advanced a little at a time until it ran ok. Problem is that with enough initial to go down the road and run halfway smoothly it kicks back on the starter restarting at operating temp. Also it runs awful on the highway if I don't have my foot lightly on the throttle because it needs the vacuum advance to have enough timing. Any ideas?
     
  2. tom3

    tom3 Veteran Member

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    I'd first hook up the vacuum advance to a manifold direct port.
     
  3. jroach

    jroach Veteran Member

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    I had tried that, but I was running less initial at that time. It was rough idling in gear and wouldn't accelerate below about 35 mph. Again it needed vacuum advance to be "all in" to run right.
     
  4. jroach

    jroach Veteran Member

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    I will try it again
     
  5. jeff swisher

    jeff swisher Veteran Member

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    If no vacuum leaks and all spark plugs are clean I would suspect a very worn out timing chain.
    Pull all spark plugs before the next drive and make sure none are sooted up.

    You could have a leaking fuel well plug on that Q jet.
    No fuel dribbling out of the boosters when idling is a must also.
    Any fuel dribbling and it is flooding and will run terrible.

    Does this still have the catalytic converter???
    Is it plugged up??
     
  6. Ihada70Z28B4

    Ihada70Z28B4 Veteran Member

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    I'd have a look at the timing curve on a distributor machine or capable engine analyzer. I assume you made sure the mechanicals inside the distributor are not sticking.
     
  7. Vettenick

    Vettenick Vettenick

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    How many miles on this motor? Have you taken a compression reading? If this motor has jumped time, all the adjustments in the world won't work. Try to line up the balancer on TDC, then check the position of the rotor to see if it lines up with #1.
     

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