i have a4x4 1999 f-150 with a4.6. i have a puff of light blue smoke at start up. sometimes if i set it will turn brown. when driving no smoke.it has always felt that i need to push it.a mechanic said check fuel regulator and pointed it out on truck.now here the kicker.the fuel pressure regulator is not a individual part like it comes up at part stores.it is made into rail.it has vacumline going to it and fuel line leaving out back.is this something that only a dept. can take care of? or am i way off base.why in the world would ford have you replace the whole rail.but then againwhats up with the catylictics on this year truck. any one got a idea.