More info please

[Google7]

Hey guys I'm looking for more info on fuel vapour system can some one point me in the right direction please

[Jay2TheRescue]

Welcome to Gassavers.Org! Honestly, that question is so vague, I don't know even where to begin. How about you start by telling us a little about yourself, your goals, type of vehicle, and how much you're willing to spend on these modifications? Most often these vapor systems wreck havoc with modern engines, and cause the computer to report trouble codes, and revert to limp home mode.

[Google7]

Ok sorry I have a 2008 gmc Sierra 4.8L I have already put on a chip that I bought from flebay the unit tricks the computer into thinking its colder out and leans out the engine and adds some power I have already noticed a gain by about 2 mpg more but like all men I want more. So I did some research on fuel vapour system. I'm not trying to replace the whole fuel system I just want to add to it to gain mpg's

[Rusty94cx]

Colder makes the ecu run richer.

[Jay2TheRescue]

Yeah, colder will make it run richer. Also, 2008 is way too new to try and add a vapor system to. The computer will override anything you try to do to it. If you really want to run on a vapor fuel, you can convert it to a dual fuel CNG/Gasoline vehicle. Your best bet is to learn to drive it more efficiently, and when you're due for new tires, get a set of nice LRR tires.

[Google7]

Yes sorry I was wrong not what I read but it does lean out the fuel
So really on an. 08 there is nothing I can do cause it's to new
There are ways to trick the ecu maybe getting o2 sensor spacers tricking the computer into thinking its not getting enough fuel but add in the vapour to compensate for it

Ideas guys I just want to be pointed in the right section of this forum so I can read and learn and get ideas

[Jay2TheRescue]

Well, the thing is this... Anything you do to trick the computer to burn leaner, can damage the engine. Lean an engine out too much, and you can blow a hole in a piston. The truck you have does have cylinder deactivation, which will help you greatly on the highway. Best thing to do is keep your speed in check. Don't go blazing down the highway at 80 MPH. Its amazing how much of a difference even slowing down 5 MPH will give you. I have a 1998 GMC K1500, and I get 18 MPG with the a/c on, cruise set on 65, and 1.000 pounds in the back.

Make sure you don't let maintenance slide. I use Mobil1 0W30, and a quality oil filter. All my fluids are synthetic. Check your tire pressure. You may want to try inflating your tires to the sidewall max pressure instead of the recommended pressure posted on the driver's door. Overall though, your biggest gains will come from changing your driving habits, not expensive vehicle modifications. I would also recommend getting a Scangauge II so you can monitor your driving, and get immediate feedback on your driving.

[Google7]

Ok my 08 is a 4.8L and its more of a basic package I have the average mpg but not the instant mpg
Plus I'm Canadian so try not to hold that against me
But thanks for the input on the tire pressure and type and the oils

[Google7]

Here's a crazy thought since I live in Manitoba Canada and we have some nice cold winters our vehicles use more fuel in winter cause the map sensor tells the computer to richen up the fuel and in summer it does better on fuel why wouldn't I be able to preheat the air in the air box before it goes into the engine even for the summer still have it preheated to say 185 in theory it should do better on fuel right

[Jay2TheRescue]

What you're referring to is called a Warm Air Intake (WAI) or Hot Air Intake (HAI) Both are excellent mods to do in average to cold climates. Not advised in hot climates though. On both my Escape and my K1500 I took out the cold air snorkels leading into the air filter box, so it sucks warmer air from the engine bay instead of cold air from outside. It does help. Pretty much what I have is what I like to call a "lazy" WAI. You can literally do it in 5 mins. Others work on creating heat shields on the exhaust manifold, and using aluminum dryer vent hose (don't use the plastic, it will melt and maybe cause a fire) direct this warm air into the air box.

What also helps with a WAI or HAI is to partially block off the grille opening so less cold air enters the engine compartment. You need to carefully watch the engine temps when you do this though.