'92 350, sluggish under load
 

Hi guys, relatively new here and hoping some old hands can lend some experience.

The motor idles fine and revs freely and without hesitation when in neutral or park. In gear the throttle is responsive only with the bare minimum of pedal input. Otherwise it just acts like fuel/air is way off and chugs along.

I checked the timing as directed and found that it was about 18 deg. advanced (with EST disconnected). I adjusted it to 0 degress TDC, reconnected the EST and it moved back to about 12 degrees. It seemed to run better that afternoon but the following day was up to its old tricks.

My next step is to pull and check the distributor rotor for weak springs, check the throttle body for sooty sensor openings etc. Anything else I should be doing?