Mods for MPGs
 

So I hear there are no performance chips for blazers, just reprogramming the PCM. Where can I get this done and what kind of mod programs are for it? Are there some physical mods you can do to the engine other than a cold air intake for more power and a little extra mpg???

"PCMforless" "Wait4me performance" "wolf tuning" Are all places to send your PCM. Getting the PCM tuned is arguably the best mod you can get for a blazer. A lot of people use Wait4me performance (including myself) or PCM for less.

Theres not a whole lot you can internally do to the engine that will be worth the small gain in MPG's. What will give you the best performance is letting the engine breathe and exhale batter. So that means getting a cold air intake and freeing up the exhaust. then getting your PCM tuned for all those upgrades.

From the pictures of Your Jimmys' engine bay - '95 4.3 , it looks to be pre-OBDII ...
where is the computer located ? If it is inside under the glove box area like mine , then the stock EEPROM chip can be removed and replaced with a performance chip . If located under the hood You can send it off for reprogramming to blackbear or others . :icon_smash:

A cold air intake WILL NOT IMPROVE FUEL ECONOMY
Fuel economy only happens at 1/3 throttle or less, yes or no?

The MAF is used to calculate the fuel to air mixture YES OR NO?

Well... Yes it will slightly.

BUT before i get you started, Yes i know the COLD AIR part means nothing and will not give you any benefits, the stock air box does a good job of bringing in cold air as it is.

The part about the cold air intake that gets you better fuel economy is the fact that they usually come with a larger intake pipe, as apposed to the 1.5" stock inlet. Some of them come with 4" pipes but that does nothing because the MAF is only about 3" ID, so dont buy into the "4 inch intake > 3 inch intake". But the reason you need the cold air part is because the engine is already getting cold air with the stock box and if you dont have a heat shield then you will actually have negative results with the hot air.

But Petty im guessing you put that 1/3 throttle part in there so you can say the bigger intake wont make a difference at 1/3 throttle, but i would have to disagree with that. the bigger intake will make it easier to pull in air no matter what the throttle position is, just you wont see as big of a difference as if you drove everywhere in WOT before and after the CAI.

Personally i have a CAI and i saw 1-2 MPG better each fill up, so i know it works. Then after i freed up my exhaust it was even better.

Just my 2 cents

If We are to assume absolutes here , yes or no might apply , but the OBDII computer uses various engine sensor input data and mapped fuel trim tables up to WOT (wide open throttle) in calculating air/fuel ratio . Any "mods" such as de-screening the mass air flow sensor or similar are temporary at best "performance mods" as the computer will adapt , essentially compensating from the lean condition introduced in an attempt to achieve the stoichiometric air–fuel mixture approximately 14.7;...
However the early '95 used speed density not a mass air system and MAP sensor comes into play - still not sure which system the OP vehicle uses ...

"Cold air intake" would lower MPG and increase performance if anything.. You're looking for a 'warm air intake'. Warm air contains less oxygen than cold air. Less fuel required to reach stoichiometric ratio= better MPG.

Now you're just makin' **** up!
:icon_naughty:
I wouldnt be repeating that around people who might be wanting hire you for atechnical job.

Smokey Yunick had it figured out.

Smokey Yunick’s Hot Vapor Fiero; 51 mpg and 0-60 in less than 6 Seconds! See and hear it run in our exclusive VIDEO! : Legendary Collector Cars

Smokey did a lot of off the wall stuff you wouldnt want to do in your car.