87 Accord Lugging in the morning every 15 miles but only when going over 60

[4G4D Store]

My sisters car is acting really weird - when she leaves work in the morning about 6am she drives home at 60+ miles an hour it starts lugging like it's loosing power after about 15 miles or so. If she stops the car on the side of the road and lets it sit running for a few minutes then she can start up again and got another 15 miles before it starts lugging again and won't hold the speed. Has anybody seen this -her car is carborated, and it only does it during the winter. Any ideas????? Please help!!!

[Tinkers4]

I think she has a carb icing problem. There is a vacuum operated "air control diaphram" on the snout of the air cleaner that lets in warm air during cold weather. The actuators on all old accords that I've seen are bad. As a quick fix, I've wired the air control door open during the winter and closed it during the summer. New diaphram is $20 - $30. Even in south Texas I've experienced icing when temp is about 35 oF and high humidity (fog).

[fpsd19]

The exhaust valves have carbon build up. When the carbon heats up the valves stick open and let all the power flow right out. Try running a can of BG44k through it.