OK, here's the deal with my 91 240 wagon, got it a few weeks ago, it was hard starting and idled ruff, changed the fuel pressure reg. Started much better and idle was much improved (still has a little hiccup now and then, but idles fine and doesn't stall when slowing down or stopping, drives fine down the road, problem is it won't start after running a while, it cranks but won't start, the other day I was out with it running around, made one stop, came out started fine, next stop came out and it cranked wouldn't start, let it sit for an hour and a half and it finally started, went back to my garage tryed to duplicate the no start, let it run for ten minutes shut it off, let it sit for a while, it started, tryed this a few times started every, so I drove it home, parked it, didn't use it all day (was a hot day) went out in the evening just to see if it would start, cranked but wouldn't start, so it sat overnight, next morning tryed it and it started right up, thought the exhaust smelled a little rich, I should mention I also changed the fuel relay switch. So at this point I'm not real comfortable taking it any where not knowing if it will start or not. Need it diagnosed. Appreciate your thoughts, thanks