Well today its pretty hot out (90F).... And im noticing that my truck has no power at all!!! I can Hammer it from a stop and it just sits there and bogs.

It usually does this when its really hot out, and it also starts up funny (Like a carberated car)..

Whats causing this???? It runs great when its warm and cold out but not hot

 

Where is your intake getting it's air from ?

 

its a volant cai, its getting it from the same place as the stock intake and down behind the head light

 

Weather conditions can make a huge difference in how your truck runs. It's not just the heat, it's also barometric pressure and humidity.

When it is hot, humid and low barometric pressure, your will definitely notice a loss in power. There are some calculators on line that will help you find out how much power you will lose in bad air compared to good. Search for Relative Air Density Calculator and you can compare various weather conditions. It can be a BIG difference in power.

Here is alink to a calculator http://wahiduddin.net/calc/calc_hp.htm Between a nice dry winter day with high pressure and a hot muggy summer day with low pressure you could lose 20% power.

That being said, make sure your cooling system is working like it should, though I would not expect a newer truck to have any problems there.

 

try living in Az where it gets 115F, see how well it runs

Its a definate difference it performance the hotter it gets, but mine never bogs or anything.

 

Yup! Agree with eveything you say alomar!

Hotter air is less dense air, and that is going to cut your fuel input too if the PCM really does maintain the correct air/fuel ratio. All of this equates to less power, but SHOULD give jonamond improved gas mileage, so there IS a good side to this!

Again, my caveat is: "If the PCM is maintaining the correct fuel/air mixture ratio". If it doesn't, possibly due to some of the settings (like WOT fuel) jonamond is using on the Edge, he may well be running way rich when he stomps it.

- Jack

 

BTW, if your air filter is over-oiled or dirty, it can make the problem worse.

The engine has to suck harder to get the air through the dirty filter. Since the engine has more vacuum, it gets more fuel. And you run too rich.

 

Ah, dirt bike, I think you MAY be wrong on this. If the engine was carburated, you're right, but fuel injection controls fuel delivery a bit differently I think.

And, if I'm wrong, EVERYONE will tell me!

- Jack

 

It may be the underhood temps in conjunction with the heat of the air coming thru the intake. I had an 05 GTO and had the same issues, and it was a common problem with those cars. On some of the forums, it suggested that the fuel was getting too hot sitting in the rails over the engine, and as you know engines like cold gas better. Not sure what you can do about it though, unless you can put heat wrap around fuel lines and the rails.

 

That's the old "vapor lock" problem. Thought it was eliminated in fuel injected vehicles.

Somehow, though, I doubt he alone has this problem due to this cause. I still suspect a WOT fuel setting that's too high for the ambient conditions.

- Jack

 

Thats a good idea... I try cranking the wot fuel down a few notices.

But it still bogs at lite throttle more so than anywhere else, Also when you go to start it, it like it chokes for a second and starts up.. ideas?

so far i
-Plugs just changed
-Clean fuel + air filter
-maf + tb cleaned

 

Holy crap

I never see those kind of temps up here

 

Temp plays a part, but barometric pressure can be an even bigger factor.

Low pressure usually occurs when a storm front is passing through or nearby. High pressure is usually associated with very clear skys.

High barometric pressure is like mother nature's supercharger. It's basically forcing air into your motor. A cold, dry, high pressure day is like nirvana for your motor, especially if you have enough fuel getting in.

Basically, the 'bad' air condtions will really hurt your power even if the fuel mixture is perfectly adjusted for the conditions. If your motor is running too rich (cold winter settings?), the effects will be magnified. Running too rich kills your power, but running too lean (leaving your summer settings on for winter) can kill your motor. So most tuners will err on teh side of being too rich for street vehicle.

 

Yeah I remember that one. On the GTO it was the plastic valve cover ornaments that trapped the heat and hindered performance. It wasnt severe and killed the engine like vapor lock, but you did notice a degradation of performance. It didnt have the same power levels as it did when it was cool outside.

 

No, I don't really have any other ideas. And dirt bike's post about barometric pressure playing a big part is correct too. (That was a great link you posted by the way. I meant to thank you for it but then forgot). :o

Interestingly, here in Arizona, even though we get literally hotter than Hell, we don't get wide barometric pressure swings. We tend to stay in the 29-30" range on the valley floor. But, we DO have mountains here too, up to 9,000 ft where I live and the pressure up on the mountain is low. I simply don't have the problems you're describing in my truck. As I recall, my WOT fuel setting is around 1.2 - 1.3.

Since you have an Edge, I assume you're using one of its "canned" tunes. Which one? Have you made any adjustments to the timing? And, has the Edge been updated with the latest firmware/version info using Lightning? (Don't use Fusion).

- Jack