''Even electronic ignition systems can get damp, especially old ones.'' '''Go to your local auto parts store. They can read the codes''' (some do it for free, some a small charge) they may also be able to tell you what the codes indicate, if not you at least have some data to start an internet search. At least that way you don't have to play musical parts.
'''Vacum hoses and connectors''' on a car that age can also be a source of intermittent problems-as they rot the walls get weak an may let in moisture, or collapse causing vacum problems.
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