1995 Cadilac Eldorado question

[janderson]

When the car is warmed up and sitting at a light it surges (best description is rpm drop below 1000, then surge to about 1400)

When driving on the highway at a constant speed I get the same kind of surging.

The check engine light is NOT on. Only 65,000 miles.

I think its ODB I so the computer may not tell me much, would it be worth it to have the codes checked? Or just go ahead and do a full tune up and see how it does afterwards?

[joe1968]

MMMM. this is a good one. Because it can be several diffrent things. If my memory serves me right Cadilac did some strange things with there engines and controls in the mid 90's. Depending on what engine you have it could be a misfire,fuel system,transmission ect.... A tune up may not be the answer but with 65k it would not be a bad idea to look at the plugs. I could be wrong but I personally would start looking for a possible vacuum leak. they can really fool you sometimes.

Joe