mileage sucks
Postmaster
Joined: Aug 2004
Posts: 2,908
Likes: 2
From: West Mansfield, Ohio
Test your EGR out, make sure your plugs are new and in working order, including plug wires. Make sure you dont have a sticky brake. That will eat up mileage in a hurry, especially with these engines.
Postmaster
Joined: Aug 2004
Posts: 2,908
Likes: 2
From: West Mansfield, Ohio
I'm not sure about newer trucks, but on my 91, it is mounted to the intake manifold right behind the alternator. Its got a plug that goes into the top and the bottom (its a wide connector.)
That module picks up a signal from the crank position sensor, and other sensors I do believe, which will determine the firing of the coil packs (if your truck is equipped with two, or one for that matter. Not sure when they discontinued the dual plug/cylinder design), and the injectors.
If your truck has the dual plug design, one of the coil packs may not be working, or picking up a signal to fire, which will kill mileage. It's like getting only half the spark to ignite the fuel.
Remember, although your CEL isnt on, your computer will still store codes. They just might not be important enough to flash the beam of "Check Engine" into your eyes!
Also, remember that cold weather kills mileage. I went from getting 28.5 MPG in the warm months on the highway, down to about 23 or 24 on the same highway in the cold.
That module picks up a signal from the crank position sensor, and other sensors I do believe, which will determine the firing of the coil packs (if your truck is equipped with two, or one for that matter. Not sure when they discontinued the dual plug/cylinder design), and the injectors.
If your truck has the dual plug design, one of the coil packs may not be working, or picking up a signal to fire, which will kill mileage. It's like getting only half the spark to ignite the fuel.
Remember, although your CEL isnt on, your computer will still store codes. They just might not be important enough to flash the beam of "Check Engine" into your eyes!
Also, remember that cold weather kills mileage. I went from getting 28.5 MPG in the warm months on the highway, down to about 23 or 24 on the same highway in the cold.
Cargo Master
Joined: Feb 2002
Posts: 2,414
Likes: 22
From: Tucson USA
my milage has also dropped, 94 4.0, but I account it to the use of the winter fuels where I refuel. I can get it back up a bit if I refuel out of my county. Dont know if you have the same problems up where you are at.
