Man I moved to Denver a year ago and my 4.6 runs like a 3.1 here.I go back to Indiana and think I have a 5.4 Woo! Is there any under the hood tricks or am I stuck without one of those high dollar programers.I mean it isn't as bad as above but I can tell a difference.

 

You may not be far off, Steve, with your equivalent size.

From the Ford towing guide:
"HIGH ALTITUDE OPERATION
Gasoline engines lose power at the rate of 3% to 4% per 1000 ft. elevation.
A reduction in gross vehicle weights and gross combination weights (of 2% per 1000 ft. elevation) is recommended to maintain performance"

It really doesn't go into any other detail, but the air is also dryer, less dense, and you're probably using the lowest/cheapest octane gas. The dealer may be able to reflash the ECU to help fix this, but you may as well get the programmer if you're already thinking about it.

-Kerry (Coloradoan at heart)

 

Thanks I'll take a look at it

 

I know what your saying...I live here in Indy myself. Have a cousin who lives in Leadville Colorado, bout 2hrs west of denver, 30min West of Breckenridge. Leadville is at 10,500ft in Elevation. Man can you tell a difference up there! Needless to say...quite a few people drive diesel engines. Much more power for the altitude.

 

I know your right.I went up Pikes Peak with this truck 2 years ago.Throttle to the floor,I think I got about 900 RPM's tops out of it.That was a trip!

 

Yup been there, and up that one also! We did this in our vehicle cuz it was a gas engine we took up pikes peak. YOu may have heard this, If its even true, might not be. But if you pull over shut your engine off...turn the ignition to the on position let it go throught its bells, whistles, dings...then start it back up that it resets the computer to adjust to the altitude. Might not be true, not sure...but been told that!

 

What is it like 19 or 20 miles to the top?I think we stoped and got out around the 13 mile area and it didn't make a difference from there I know.

 

You figure you take the rated hp and drop 18-22% right off the bat for parasitic losses (I'm assuming an auto tranny here) and that's what you're getting at the rear wheels at sea level. By the time you're at the top of a pass or sitting on Pikes Peak, Mt. Evans, or Trail Ridge you're lucky if you have 50% of 231 hp. Now if you had a 'yota or other small car... that hp number would be stock and about right for the weight. For a 4500-5000 lb truck, well 115 hp is not too good.

The truck's ECU is going to try to match whatever's coming in with whatever's going out (MAF + O2 = fuel injected). What really's going on is somewhat more difficult than that. Made simple, you're also going to get a lot less fuel into the system due to the lower air pressure and less density. The O2 sensors don't want a rich mixture either... so you end up with less hp.

Simply turning off the truck is not going to make it relearn anything. If you haven't had the battery cable off since your move, you may want to try that route. In your owner's manual you can find which under hood fuse powers the ECU and pull it and leave it out for a few hours, that way you won't lose your radio presets or your trip ODO stuff. It may be an old wife's tale for all I know, I pretty sure it resets your ECU's "learned" behavior.

My dad's never had a problem with his 5.4 for power ('02 S'crew FX4), but he'd love a steeper gear than a 3.55 when towing. Maybe that's another route you can go.

-Kerry

 

Disconnect for a couple of hours?I've been hearing a lot of that lately.What happend to just pullin the neg.off for 5 or 10 secs.
I know I just put a new battery in a month or so ago and that didn't do anything for it,took about five mins. to to that.

 

I'm not sure if this is true, that's why I said it's probably an old wife's tale.

I think there may be a capacitor in that circuit providing a source to maintain the memory if you have a temporary loss, ie battery change out. If you leave it disconnected, the capacitor discharges to the point that the memory is lost, then it no longer has the "learned" behavior in memory.

-Kerry

 

I will give it a try!Thanks