What a great feat, the truck weathered the 6200ft climb but I ran into a strange issue with the truck when it came to a grade greater than 18 degrees, what do you guys / gals think.
I had the truck in low gear and was going about 20 miles and hour with about 1800 rpms, when the truck was entering a steep incline, around 18 - 22 degrees I had the gas petal floored and the truck seems to stay at about 1800 rpms and seemed as it would not move, it was going about 2-3 miles an hour. I placed the truck into 4 wheel drive and it accomlish nothing. I had to put the truck into 4 wheel low to get the truck moving. So my question, was this caused by not having a low enough gear? Somehting not right with the limited slip? I was confused, but glad 4 wheel low worked, could you imagine the shame if I had to turn around and head down the mountain... any help or ideas on why this is so peoples? Thanks a bunch!


https://www.f150online.com/galleries...y.cfm?gnum=752

 

First of all is this a 5.4 or a 4.6? Even if its the smaller 8 I still don't think that sound right. One factor may be the altitude. At that hight altitude, the engin will produce less power. But you may have a issue with the mass air sensor as well with that little bit of power. I don't see an 18% grade as that much. I have gone offroading in high desert with little problem and went up hills a lot steeper than that. I have the 5.4 4x4.

So maybe it is a problem. Or the computer just didn't have time to adjust to the higher altitude. Dosen't sound right to me. Also you may want to change your gas brand???

 

I've done ~20 deg. before in 4WD low (@3000 ft. elevation) and I hardly had to mash the gas pedal at all. Granted, I didn't climb this particular grade in 4WD high due to the very rough nature of the hill, but I don't think it would have had a problem had the hill been a smooth incline and I was in 4WD low.

 

dcovell, good point. It is a 5.4 engine, I forget to mention that I only experianced this issue when I was over 4k feet high. below that it ran like a champ. It is quite possible that the computer didnt have time to calcuate the differance as the climb to 6k was done in 8 miles with the last 2k feet being done in less than 1 1/2 miles. Not sure what a mass air sensor is?

 

Sounds like your truck needs some warranty work. I drive up past 10,000 feet on occassion and while I experience significant power loss, when compared to sea level, it's not so much that the truck can't accelerate.

At 4,000', you really shouldn't feel all that much difference.

 

I agree with Dennis, I regularly go from sea level to 6000 feet and have taken the truck from sea level to over 13000 feet in 1 1/2 hour of driving. I have a 4.6 4X4 and lose some power obviously but not as much as that.

 

I agree with the others. Something is wrong. I live at 4K and have driven well over 10K on a number of occassions so far with the truck. No problem at all. Take it to the dealer.

 

FewScrewsLoose,

At least you got to climb, I drove up with my wife and daughter. Reaching the toll gate we read that visability was only 50 ft so we declined to go....I wasn't happy...i wanted to drive up...anytime you want company on your return trip let me know.

Ed

 

Thanks for the comments guys! I will schedual an appointment tommorow to get this looked at, can someone stilll help me out with what a mass air sensor is? thanks!

 

It is located in the air inlet tube right after the airfilter housing. Sometimes they get dirty or go bad and tell the computer there is no air or some other wrong data.

There are so many damm parts under the hood that have to do with the fuel to air mixture and the smog systems that only a diagnostics computer will find the problem, and I would guess thats the first thing your dealer/mechanic will do.

 

MAFS Mass Air Flow Sensor.

It is right after the air filter, if you still have the stock air box on, it is in the half closest to the T/B ( Throttle Body ), you will see about 8 wires or so going into a gromet, this is the connector for the MAFS.

The MAFS coupled with the Intake temp sensor calc how much fuel to put in the flow at the T/B ( or how much to retard the timming if the intake temp is high ) so you don't create detonation.
Ford and Chevy use this, Dodge I think still uses a consistant velocity method ( no MAFS in a Dodge, or at least the 95 didn't ).

This is my 1 cent tour, someone should be along to correct me on this, if I screwed the pooch on it.

It got me, when I went back to a Ford, last Ford I had was a '81 F-100 I-6, and I don't recall seeing this on it, that had the tuna can air cleaner on it.

 

I'll add a little bit to Scully's explanation.

The sensor is basically a wire. Platinum, I'm guessing. It heats up. The more air that flows past it, the cooler the wire gets. The cooler the wire, the lower the resistance and the system can sense this difference and calculate the amount of air going into the engine. So, if it's defective or dirty, the wire might heat up more than normal which means the computer will think that there is less air entering the engine, so it leans out the fuel injection system. Less fuel, leaves you with less power.

I think.

 

Good Lord! thanks for all the input guys! I miss the days of a stripped down 302 small block that I could actually work on! today I open the hood and all I see is plastic. I have no idea on what all this stuff is! "an engine I guess :o)"