QuestionI have a 2000 Chevy C3500 dually. It has a 7.4 with an auto trans. (4L80E) Over the last few months the truck has gotten increasingly harder to start at certain times. If I go to start it cold after sitting over night, it will fire right up. However, if I drive it for a while, shut it off for an hour or so, then try to start it, it has to turn over many times and will finally stumble to an idle. When it starts, there is sometimes dark smoke from the exhaust for an instant. After it is running, everything is fine. It will repeat the same thing just about every time I drive it.
AnswerHi
I would look at the fuel pressure regulator. Make sure there is NO fuel in the vacuum side of the regulator.
If so, it needs to be replaced.
If it checks out OK, check the entire fuel system, pump, filter, lines, injectors, etc... as the dark or black smoke would tell me it is running rich (too much fuel,OR not enough air).
I would also check the Mass Air Flow sensor, and the entire air induction system (filter, tube, under filter, etc...). I know this sounds funny, but check and make sure there is not a plastic grocery type bag in the induction system. I have seen $1000's$ spent on repairs when it was a plastic bag in the induction system.
I hope this helps.
Good Luck
PAwl
