Gene4.6L

[:@]My 2000 4.6L will not start sometimes after it has been driven. After it sits for about an hour it will fire back up. I put a New fuel pump, filter and even cleaned out the fuel tank and replaced the fuel filler neck since it was rusted out where Ford put a plastic wire loom around the pipe. (Might want to see if any of yours is going to have that problem.)Leaking bad...
What would make it not start like that? The dealer has no Idea and tells me to bring it to them while it is having the problem, but by the time I get it there is will start.
What else do I need to replace or look for?
Can someone help?

Evenexchange

Does it.. turn over? Does the starter try to start the engine or.. do you click over and nothing happens?

Gene4.6L

It cranks over fine it just won't fire up. I don't know if a sensor is going out or what. After is sits for a while it will start and run. If I drive it for a while and then shut it off then it won't start again until is sits for a while. Sometimes if will not have this problem, but it seems to be happening more ofter now.

Evenexchange

It's some kind of sensor that is malfunctioning. Let me put it this way: The computer is getting a message to not fire up that engine because something isn't reading right. I seriousely doubt it's anything mechanical. I mean, that's my guess.. strange problem this is. I haven't heard of this ever happening so start looking at things that usually dont go bad.

Gene4.6L

Where do I start? Is there some kind of low oil sensor that might cause this problem? or do you think it might be the computer?

Evenexchange

Ah jeez man it's really hard to say.. I seriousely wish I could help cuz I know ALL about having frustrating issues with my car. I got the same year as you too.. 2000 GT.

I mean.. its gotta be something that is relinquished once the car cools off.. Umm.. Some sensor might be reading hot? It might even be the main fuel relay under the dash.. I know hondas and stuff have a lot of trouble with those going bad and not starting when the engine/weather is hot.

What you have to think about though is when your engine is hot, fuel cant circulate well cuz of the way vapour obstructs it's workings. I mean.. a solution to this is use a high quality coolant.. you might have fuel line problems too (possible) I would try to change all your coolant honestly. It's cheap, and seriousely worth a shot.

Also, a thing to keep in mind though is that with FI engines, the fuel remians in the injectors at high pressure.. so where I was talking about vapours before, FI engines arent as suseptible to that problem.

Gene4.6L

That might very well be the problem, because my water pump started leaking a little and I have just been adding water to fill it back up. It might be running hotter than normal, but does not show it on the gauge. I will try this to be sure.

Evenexchange

I researched your problem and found that many people replaced their fuel relay/fuel pressure accumulator and the problem completely vanished.

If you want to take a look.. I think you might have a winner here:

http://www.mercedesforum.com/archive...ok-4871-1.html

Evenexchange

Yes, so I would say if you arent running any antifreeze, that might be causing your problems. I would say try the new coolant mixture (high quality) then move on to the forum thread posted about the duel relay replacement.

Gene4.6L

is that the one under the dash?