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Discussion Starter · #1 ·
The 429 is still not running right. I have installed a Qjet that runs fairly well but is hard to keep running when it is cold. The idle speeds up as the engine warms up. It will run fairly smooth when warm but when I give it gas it misses and has a bad afterfire. I have a resently installed pertronix ignition. I checked the valve timing and the vibration damper has not slipped and shows TDC when the valves at shut. Timing is set at 8 BTDC. I can't find a timed vacuum on the carb. I talked to a carb specialist and he told me which ports should be timed. Neither one was so I have vacuum on the vacuum advance at idle. I can't figure why I would have vacuum on a timed port. I believe that might be causing the afterfire and the pour idle. Any help would be greatly appreciated.
 

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Try finding another port on the intake manifold itself to take the vacuum from to use on the vacuum advance can. You might need to use a "T" in the line if the vacuum source is being used for another accessory.

Don't use the same vacuum source as the power brakes or the PCV valve. If you see one that's used for the interior HVAC- it would be fine to use, for instance.

There should be a "full-time" vacuum source on the Q-Jet, but exactly which port is hard to say- there were a lot of different Q-Jets used throughout the years. Using your finger or a vacuum gage should be all that's needed, but like I said, you can pick up manifold vacuum elsewhere.

Let us know how it goes.
 

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Discussion Starter · #3 ·
It appears that I had the wrong gasket for the Qjet. It left some areas uncovered that should have been covered. After checking my timing it looked like it was not firing on #1 correctly. I set the motor to TDC and turned the distributor clockwise (dist rotates counterclockwise) until I heard it spark. Now it won't start. It appeared that before I made the change it was firing after it should be but the timing light showed it was right. I will need to move it back and see if it will start.
 
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