1989 Volvo 240. Last week during a winter storm and driving over bumpy packed ice, I was losing power (misfiring and constant on/off sound of the engine). I had to pump the gas pedal to get anywhere slow. I pulled into a parking lot for the night and got a ride home. The next morning it started fine but I still had it towed to the dealer just in case. They replaced the coil wire, distributor and cap, spark plug wires, spark plugs, and cleaned the throttle body. They didn't see the actual issue but sprayed water on top of the engine and supposedly it stumbled from that.

Today there was another winter storm, I got a mile from work and the same problem was occurring again. I made it to a service station where I was actually able to show the mechanic the issue. He is looking at it tomorrow but off the top of his head he guessed it is either the coil or a fuel issue.

Anything else I should ask him to look at specifically? I don't want parts thrown at this again.