... but now that the temp's here have been over a 100 for a week, I seem to be losing a ton of power. I mean I can't imangie why? 107 on temp readout, to AC's running at max plus radio blaring to over power 2 AC's running on full, plus I know how fast I move outside, and I don't weigh in near 3 tons

So I probably just answered my own question, but the off the line power really sucks! couldn't even keep up with a surburpin the other day

 

I notice the same affect on mine here in the Mid-Atlantic (see MODS below) For additional information, you may want to read some other threads about aftermarket intakes. They debate the notion that letting hotter air into the engine reduces engine performance.

Over the last week, we've had mornings with temps ranging from the 50's with no humidity to the 70's with 90% humidity. I definitely notice the Expy likes the cooler\dryer weather. Than again, maybe I'm dillusional!

Hey, otherwise, CHIP that sucker and take on the Surburban!

 

I read somewhere why Fords do that. Because of the extremely hot air, it's compensates by changing the A/F ratio to extremely rich to avoid detonation.

One thing, last year, pre Airaid, I could go almost throttle to the floor and barely move. This year, it's not as bad. Today it's about 106 out where I live and has been over or near 100 for several days.

The heat does suck, but that's life I guess. The alternative, although won't eliminate it, is a Blower!

 

I live in Phoenix and noticed the same in our recently purchased '01 Expy so took it right back to the dealer. Power is pittiful at easy acceleration on VERY hot days. The explanation I got was that when the fan clutch kicks in, it absolutely sucks the power from the engine. If you all notice, when the power goes away, the engine RPMS are up and you can definately hear the whine from the fan running. So, not anything they were willing to do to help. It really only happens to our Expy on extremely hot days (anything +108 or so). It's livable (I'm in not mood to ever match my Expy against any other on the road - too old I guess), so we've accepted that the summers will be a bit tougher on acclerating.

 

....not to this extreme. The fan certainly drags and you can surely hear it, but I don't think that's the whole story. I've already learned that it's really hard to find someone at a dealer that really knows the whole story with these things. For most of them, it's a job, they done whats needed and go home. There's more people on this board that have enough interest to investigate and learn the nitty gritty.

I've had my fan kick in solid and still have much better power. I can't imagine that it would go to the extreme of 1/2 to 3/4 throttle just to get it to move. I may try electric fans soon so that will be the tell tale.

Another thing, like I mentioned, this year with the Airaid it's not near as bad. I think the fact that a lot more air is availble, the PCM isn't not compensating as much. Although when gets really hot, I have this slight "whine" at idle. You can hear the air in the TB but I just try to pretend it's a blower whine to imagine what that would be like.

 

The power (or lack of) is certainly a matter of the computer rescheduling to the heat and humidity. The theory's the same with flying turbine aircraft. Hot and humid = lost power and higher fuel consumption. Love fall and winter. Fact of life

 

Prior to the Expedition I had a '98 Durango 5.9L... When the Thermostat was above 205 or so, the cluth fan would kick in and BOOM - NO POWER WHATEVER..... The response I got from everybody at that time was to install a cooler thermostat to keep the temp down.... I noticed over the past weekend that the Expy does the same thing..... I guess we have 2 options.... Maybe 3... Cooler Thermostat - BIGGER Radiator or even Redline water-wetter.....

 

The fix for this loss of power in the heat is simple. One A/C vent ducked to the air intake of the engine and the clutched fan removed and two electric ones installed!! Just trying to help.....