[carnut]

Having no history of services performed, i would suspect fuel filter and/ or plugged cat converter. You need to verify timing is at at least 10 degrees btdc preferrably 12 degrees, for normal performance. To verify timing, disconnect the green connector behind the distributor, then check the base timing. Must be between 10 and 12 degrees, reconnect green connector, engine off.
They rarely flood but can be running too lean which can feel the same. Also check for fuel pressure to be in the normal range. With the engine running, remove the air cleaner lid. Look down and you should see 2 distinct sprays of fuel from both injectors. I've seen the adaptor under the aircleaner pinch this injector harness which can short out one of the two injectors.