1987 crx

I have a 1987 CRX, recently had the carburetor rebuilt among other repairs. Suddenly I was driving and it seemed to want to lose power, chugging along, then it would pop into to normal. Any ideas, my mechanics can’t pinpoint it, of course they drove it and it didn’t act up.

When was the last time that the fuel filter was replaced? If you cannot remember, or if you can verify that the filter has been in place for more than 30k, it is time for a filter change.