My 2002 Accord EX 6 Cylinder had to sit for 6 months with someone starting it every few weeks. The last few times, they said the engine roared while in neutral like someone was stepping on the gas. Now it has a cold start problem. It will only start at mid day when the sun has been warming up the hood. The car has 170,000 miles. The mpg was bad the last time I drove it which was a cross country trip. Nothing is showing on the computer, which had to be reset. Any ideas?