Re: Rough idle after rebuilding carb

Posted by Owen_Dyneto On 2014/10/30 9:52:38

Just to validate. I was hooking the gauge up to the port that's right by the idle jet screws.

Incorrect - that port if I understand you correctly is for the distributor vacuum advance and may be partially (or fully) blocked when the throttle plates are closed. You need to take the vacuum directly on the intake manifold. If there isn't a service plug somewhere (usually is) you can take it by disconnecting the intake to vacuum booster (fuel pump) line and attaching the gauge to the manifold there.

Try readjusting your idle mixture with the vacuum gauge properly connected. If that doesn't solve it, then consider taking the carb apart and cleaning the idle mixture passages; compressed air aided by a bit of carb cleaner solvent should do it after removing the idle mixture screws - make sure the solvent/air blast emerges at the ports inside the throttle bore. If not, try blowing in the reverse direction.