I didn’t think of that, but it is a high probability. Timing retarded acts just like that. Could be a sloppy distributor as well.
Although, that bit about hitting bumps and A/C really point to bad electrical connections. Check all grounds, clean them all up, report back after that. There are a number of grounds that affect the engine, do a search on teamcapri to find all you can. Like modern healthcare, with a Capri, you are your own best advocate- you must research this stuff yourself. There just aren’t any shops that would know about that car anymore.