Is dealer obligated to fix problem on 1988 model if recall is for 1990 model?

What is your question?

Recall 90V177000 describes the problem with my 1988 model. Engine reaces at start up. Not always but more frequently lately. Sometimes takes several attempts at re-start to get idle speed down to normal. Is dealer obligated to fix? The Recall says it's for 1990 models? How difficult is replacing the TPS sensor(s)?