I am experiencing poor fuel mileage around 13mpg and as of late my truck falls on her face if I stand on it. It will start to go then blaaah then almost immediatly it starts pullin like crazy again. This just started happening about a month ago. I have replaced the CPS, IPR, and IPS already with no change in the stumble or fuel mileage. As far as mileage is concerned I get about 15-16 on the highway at 74 mph. I have a Diablo programmer and have my truck programmed to the 60hp setting its been set there for over a year. I also have a Magnaflow 4" exhaust and the quick filter mod. My exhaust temp never gets over 1100 even when pulling a heavy trailer up a hill. The truck starts and runs fine with the exception of the stumble and mileage.

Just wondering if anyone had any ideas as how to rid my truck of the stumble and get better MPG.

Oh yea under light acelleration it doesn't have any stumble or its so small I barely notice it.

Thanks,
Chris

 

Mine does it occasionally, but at half throttle. I talked to my friend who is a diesel mechanic and he says it's the throttle position sensor (which on the diesels is the throttle petal itself). He says replacing that will solve my problem. The contact points can wear out, which would give you zero throttle, and then right back on (without moving your foot). Hope that helps, let me know if it does, since I haven't done it yet to mine. Tommy

 

Thanks Tommy - I dont think that is it because if I give her 1/2 throttle its a smaller stumble then if I mash the pedal to the floor. And If I give her wide open (so to say since the diesel is always wide open) and hold it there it will like die and almost instantly go like he11?

Its not like I am giving her every stoplight but when a chev pulls up next to me and thinks he can haul me I would like to show him up. But the hesitation almost always gives the other truck or car an advantage and makes my Ford look like a pooch.
Thanks,
Chris