Could be a number of things but the thermal vacuum switch shouldn't be on the list. A bad accelerator enrichment pump on the carb, a bad vac advance on the distributor, clogged jets, engine tune, a bad coil, spark plugs out of spec (or any of the wear and tear components of the ignition system), gummed up EGR valve on the carb, accelerator cable not adjusted properly... plenty of places to start looking.
Bookmarks