Got a new 69 gtx 440 and when on the throttle it hits hard but I hit 4500 rpm it starts popping and cracking won't go past 4500 rpm. Any idea what could cause this. I swapped ignition boxes and put a fbo one on it same issue. Has a new carb as well. Could something in distributor be the issue or maybe coil. It has a stock distributor and msd coil but coil runs through a ballist. I didn't think you would run the msd coil through ballist it needs full 12 volts.
Can't rev over 4500 rpm
- Thread starter 19 69 GTX
- Start date
rmchrgr
Well-Known Member
What is the timing set at?
Stock points distributor? Can definately be point float at that RPM.
Could be a lot of things but if your distributor is pretty old I would pull the cap and see if there is side to side play in the shaft, signaling a worn upper bushing. I think the ballast resister is OK with just an MSD coil.
dvw
Well-Known Member
Have you tried disconnecting the tach? alternator? Had 2 of these recently. One we figured out. The other has has extensive testing and still has the issue.
Doug
Doug
Not sure I'm going over to a buddies today and see where it is.
It's electronic ignition
That's what I was wondering
Nevada dan
Well-Known Member
My sisters 340 duster sat for 30 years , had to replace the valve springs, ran like a raped ape after that , but I agree with the others to start with the distributor
rmchrgr
Well-Known Member
Was going to suggest valve springs...
rmchrgr
Well-Known Member
Also check the plugs for condition and check the gap.
Steven Bowers
Well-Known Member
I had similar issues with my engine…went to heavy valve springs….man what a difference it made….
Power wire to ECU not on 12v side of ballast resistor?
Not sure car has been rewired with aftermarket kit.
The ballast requirement should be dependent on the fbo box . I do not know what they like. (Instructions?)
I had the stock orange box on it and swapped to the fbo box a friend had and it did the same thing
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