I have a 2002 ford supercrew that starts very inconsistently. It cranks over very well but will not start. I wait 30 seconds or turn the key back and forth a few times and than it starts. However there is no consistency. Any suggestions. In general will a fuel pump either work or not.

This generally happens when the vehicle is cold and during the winter but not always. It will start and I can drive it for five to ten minutes to my destination. Then 30 minutes later I will have the same problem. So to answer your question it does happen after the vehicle has been driven. The fuel pressure was tested last year and showed OK. As I mentioned their is no consistency. Sometimes it starts in the morning then at noon it won't start and vise versa. If turning the key back and forth helps the starting what part needs to be replaced. This generally happens when the vehicle is cold and during the winter but not always. It will start and I can drive it for five to ten minutes to my destination. Then 30 minutes later I will have the same problem. So to answer your question it does happen after the vehicle has been driven. The fuel pressure was tested last year and showed OK. As I mentioned their is no consistency. Sometimes it starts in the morning then at noon it won't start and vise versa. If turning the key back and forth helps the starting what part needs to be replaced.

Turning the key on and off a few times will give the system that extra prime if required to get up to pressure. My guess would be that vehicle had been running for a while previous to fuel pressure test because you probably had to drive there to have it done. Best scenario there would be to leave the truck so that it can be tested first try in the morning. There's a couple of reasons I prefer that. If an injector or injectors are leaking down while sitting, it will reduce fuel pressure and make starting hard, thus gauge when installed before may show a little low initially, but register a little more pressure each time key cycled to on, until it reaches recommended pressure, then starting happens as it should. Also, if injector(s) leaking down after shutting engine off, then pressure gauge should also show that if left hooked up for a while and monitored from time to time. If you go somewhere, stop and depending on when you come back out to start it, it may even act like a flooded engine if the injector(s) are leaking, thus taking more time to turn over before it fires up. Personally, if I hadn't changed my fuel filter in the last while, I'd start with that, (simple things first) to make sure it is not restricting flow in any way. Then double check that fuel pressure as described, and maybe even pull a few plugs to see if any look wet with fuel when it won't start easy. That would be a good indication of which injectors may be leaking down. One thing I would do though, if it looks like a possible leaky injector, is try a good injector flush, before replacing injectors if that's the cause. Keep me posted if /when you find anything. Turning the key on and off a few times will give the system that extra prime if required to get up to pressure. My guess would be that vehicle had been running for a while previous to fuel pressure test because you probably had to drive there to have it done. Best scenario there would be to leave the truck so that it can be tested first try in the morning. There's a couple of reasons I prefer that. If an injector or injectors are leaking down while sitting, it will reduce fuel pressure and make starting hard, thus gauge when installed before may show a little low initially, but register a little more pressure each time key cycled to on, until it reaches recommended pressure, then starting happens as it should. Also, if injector(s) leaking down after shutting engine off, then pressure gauge should also show that if left hooked up for a while and monitored from time to time. If you go somewhere, stop and depending on when you come back out to start it, it may even act like a flooded engine if the injector(s) are leaking, thus taking more time to turn over before it fires up. Personally, if I hadn't changed my fuel filter in the last while, I'd start with that, (simple things first) to make sure it is not restricting flow in any way. Then double check that fuel pressure as described, and maybe even pull a few plugs to see if any look wet with fuel when it won't start easy. That would be a good indication of which injectors may be leaking down. One thing I would do though, if it looks like a possible leaky injector, is try a good injector flush, before replacing injectors if that's the cause. Keep me posted if /when you find anything.