I have 1994 Cadillac SLS.. When I start the car it idles up and down fast and/or slow, then it idles up and down when I'm driving and sometimes dies but starts right bk up and I hear a little backfire
Could be a dirty throttle body or ISC unit, unregulated air leak, might be a good idea to have the codes read, on an ODB1 Cadi that has to be done via the information control center, if you've never done that I would recommend taking it to a shop that you trust.
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