The sweep pattern you describe is no codes stored and ecu functioning ok.

In the words of Bill, the drunken a&p who taught me a lot of what I know, 90% of all problems are electrical. The other 50% are stupidity.

If you have a holed cap, send it off. You have an intermittent fault, probably a trace almost eaten thru on the circuit board.

Or, a quick search of car-part.com has used ecu's for your model for from 150 to 350 bucks. Rebuilt sounds better to me. One other possibility is a failing ecu relay.

Not responsible for advice not taken...