02 F150 hard start/rough idle

[ga93sle]

So my truck has been doing this since I bought it, but it's slowly but surely getting worse. It starts perfectly fine when it's been sitting overnight, but if you try and start it after it's been driven it starts very hard, engine temp doesn't seem to be the deciding factor, just period of time since driven last. It also idles pretty rough when it's warm, but won't completely die out. It's also started to backfire every once in a while when it does the hard start. It has a CEL, but it's for "keep alive voltage too low", seemingly unrelated to me. Put new plugs in it right after I got it and all 3 on the left bank smelled like gas, I'm sure the new plugs are ruined . Any ideas? I'm thinking EGR or FPR... BTW, it's a 2002 XL 4.2L V6, auto, 4x4 if that helps.

[PaulyGXP]

I guess I would try cycling the key a few times before you start it. The fuel pump may not be holding the pressure in the line so the fuel bleeds away from the injectors. Could also be the injectors not holding pressure and bleeding into the motor. I have seen this issue on several forums, but never a definite answer. Best answer seems to be to upgrade to 4.6 or 5.4. Same gas mileage, more power, almost bulletproof.

[SSEiMan01]

Had a guy in my work asking for advice on a similar issue a few days ago, Chris. I don't remember what my boss (Ford guy) said it was, but it was fuel related indeed. If I remember tomorrow I'll ask him again.

[ga93sle]

I don't think it's the pump bleeding off, cause the longer it sits the better it starts. I thought about injectors but thought it odd that all 3 on one bank would go bad. I don't have much reason to upgrade, especially not for such a simple problem. This thing actually gets awesome gas mileage, way better than any 5.4 I've seen, and power isn't an issue, I never really work it that hard.

[Jrs3800]

You need to look into the keep alive voltage and see what that circuit is... As well I am curious about the 3 plugs being wet... IIRC the 4.2 should be a sequential fuel injected engine the the 3 wet plugs concerns me.. wondering if there is an issue with the coil pack or control module..

I think you may need a good scan to see whats going on with the truck..