I have just acquired an 80 series auto with a 1HDT motor. Sometimes when it's in drive with my foot on the brake it sets up a violent shudder. It's only intermittent and sometimes when it starts doing it I can stop it by turning off the aircon. As far as I can tell it's mostly caused by the natural chug-chug of the motor at idle that translates into drive pulses in the drivetrain. The question is what do I do about it? Do I just increase the idle speed? I plan to add a lift pump to it, as I have found that these engines run better with a lift pump, and hopefully the upstream pressure will smooth the idle
