Hesitates going up hills

2007 FORD EXPEDITION

129,000 MILES • V8 • 4WD • AUTOMATIC

WHITETAILFREAK

MEMBER
5 POSTS

Hesitates going up hills only. It is not all the time but once in awhile what happens is as you progress up the hill it starts to bog down and you can press the accelerator all the way to the floor and the vehicle dose not respond to it, then all of a sudden it snaps right back and takes off. I have replaced the fuel pump, strainer, fuel filter, plug coils and coil boots. I am a pretty avid and knowledgeable tech but this one gets me. I hope you can give me some idea of where to turn next.

Sep 30, 2009 at 9:46 AM

JACOBANDNICKOLAS

✓ASE Certified Mechanic
110,194 POSTS

Have you checked the catalytic converter to make sure it is not loose inside and plugging the exhaust at times?

Oct 28, 2009 at 12:59 PM

WHITETAILFREAK

MEMBER
5 POSTS

Yes, I have. It seems to be fine. Ford dealership said something about a transmission re-calibration. Any ideas on that?

Oct 30, 2009 at 10:55 AM

TOLEDOGIRL98_2000

MEMBER
1 POST

I had this same exact problem on my 1997 Expedition and changed the fuel filter, fuel pump, tune-up etc. went to several mechanics and only one could figure out the problem only because he had ran into the same problem with another vehicle in the past. It ended up being the the Mass Air Flow Sensor. It only cost me I think it was around $80.00. After that I had all my power back and was zooming up hills like it was supposed to.

Nov 19, 2009 at 6:38 PM

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