I've got a 1994 Accord Ex, 4cyl, 5spd, 185k, well maintained that sometimes starts and sometimes it doesn't. When it won't start, it cranks, acts like it's not getting fuel and once in a great while backfires. If allowed to rest for an hour or so it usually starts just fine. Weather doesn't seem to affect it. The problem cropped up in the fall and continues through bitterly cold weather.

I first thought it might be water in the fuel, so I ran a commercial alcohol based solution through a couple of tanks. I also used a good quality injector cleaner in a tank. Nothing has made a difference.

On a general car repair forum, someone suggested it might be the fuel pump relay. I have no idea where it is, or how to check it, so I'm asking, no, pleading for help.

Thanks everyone

 

Fuel pump relay (search "main relay") is located near the driver's left knee. (not sure what they do for RHD cars like England)

The most basic test is easy - listen for the fuel pump.
- turn off all noisemakers like stereo & ventilation (pump isn't very loud)
- turn the key to "RUN" but don't immediately continue to "START"
- listen for fuel pump to run for 2 seconds then stop
- (this will correspond to the main relay clicking on & off)

This is better in General Tech, so I'll move it.