My truck trembles when it first starts, but drives okay after that, though it does have some hesitation. I was thinking it might be the spark plugs or fuel filter might be to blame, but I am not sure.
These symptoms point towards fuel delivery, Have a certified mechanic test your fuel pressure I have a feeling it would be out of specification. Most port fuel injection systems run at about 35-50 psi depending on make and model and should hold that pressure after the key is turned off, the fuel pressure regulators job is to open and release and pressure over spec. If the fuel pressure regulator is leaking long cranking times and hard starts would be expected as the engine is not getting enough fuel, other causes for fuel starvation could be a clogged fuel filter, pinched pressure line or faulty fuel pump.
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