Ranger rev limiter?

[guismo]

Hello, I am new here. and Iam in need of some help.
I have a 2001 Ranger xlt 4x4 w/ 4.0L V6 sohc. Love my truck .... I'v had her for 3yrs. My gas milage has dropped from 21mpg to 13mpg. literaly overnight. I have had the air/oil/fuel filters replaced. allighnment and new tires/ balljoints. METICULOUS about my truck maintenece. I have been taking it to the dealership for a year and (no no mine did the same) that's all I get.
I have taken it to a garage and the owner spent four hours on the lift.
YEAH an answer..

he said
"Diagnose Engine w/ scan tool. No codes found, however, Increase idle speed to 3500 rpm and engine starts to cut out, long term fuel trim high@ idle, drops to negative values when rpm@2000, INDICATED LEAK IN MANIFOLD"

Warranty ends in 22 days.

Dealership said that was the rev-limiter cutting out the engine, He walks out to a catilac and starts it up, to the floor wa-n wa-n wa-n wa-n. "Ok" I said BUT mine sounds much diff. like it's choking instead wa-k wa-k wa-k

Does any one elsed engine cut out at 3000rpm mine wont go past it in park or neutral.
I need some help a second oppinion. pls thanks guismo.

 

[hunterdan]

Yes, my dads 2004 won't rev past 3k in park or neutral, same motor. If the lomg term fuel trim is off, then there is probably a vacuum leak or MAF problem.

Dan

 

[guismo]

Hunter Dan Thanks for the input. I'm trying to go to the dealership w/ as much info as poss.
What year is your dads truck?