Okay, this is an automotive question. I hope this is the right place for it.

We have a 1996 Honda Civic, fuel injection, 175k miles. It has been running like a top since we bought it (at 100k miles) but now it has developed a peculiar glitch.

If I start it in the morning and drive to the grocery store, it won't restart when I leave the store. It will crank and crank and crank -- no end of battery. But it doesn't fire. The store is about 1.5 miles from home, the streets are all 25mph which I usually drive at 20.

However if I drive it at high speeds for a few miles, not even very many more, it re-starts fine. If you allow it to cool all the way down, it starts fine. If you only drive a couple of blocks, turn it off, wait a short bit, then try to restart it, it starts fine.

It seems like the problem is if it heats up a little bit, but not all the way.

I took it to the new dealer in town (since my favourite mechanic died and his successors had their shop closed when they were caught running drugs), and they had it a week and couldn't find what was wrong. They did charge me to clean out carbon deposits from the head ($250) and replace the coil ($250) but that didn't fix it. They checked the cranking power of the battery and it had 380 cold cranking amps (I think that's the number they said) and they said that was certainly not the problem.

I got it back from them, unfixed, and am just making sure I get it out on the highway any trip I'm on (it's a slight detour from the grocery store but not much more than a mile or two more).

Does anybody have any idea what could be causing this?