I was wondering for upgrades that require correcting the engines fuel curve (stroker, ect.) which would do it more efficiently (like one effects the fuel curve in a smaller range, etc.) or is there little to no diffrence?  

For a stroker you would want to use larger injectors. It is an increase in volume of fuel that you want.

The MAP sensor's purpose is to provide input to the ECM to change the pulse width of the injector, which does increase volume, but an injector can only flow so much.

If the injectors are sized correctly, then the fuel maps and timing maps most likely won't need modifying.

More pressure is not necessarily more volume. And injectors should only run at 80% duty cycle.

Raising the fuel pressure and running an adjustable MAP (fooler box) is goofy. Running either or combining both, do not make up for not having correctly sized injectors. They are both cheap trick bandaids and at most would be used for fine tuning and not power producing mods.  

ya i figured the injector was a given being that you need it for a stroker, but a all the strokers ive seen online they say to use either a adjustible fuel pressure regulator or adjustible MAP sensor to fine tune the air fuel ratio. i all ready have an AFR monitor. hope this info helps...  

It Depends on the year of the fuel injection system that is being used for the stroker. The 87-95 years have a 39psi stock fuel pump. '96 and later have a 49psi stock fuel pump.

Injector flow is based on pressure. So, in order to choose injectors you need to know about the pressure.

Most stroker info that I have read don't suggest needing to increase the pressure or using a fooler box MAP for '96 and later.

And when it gets right down to it, I think you might want a programmer to fine tune everything.

The adjustable MAP is really just a simple device to richen up the mixture a bit. Like turning the screw on a carb. But doesn't make it like you're running a bigger carb.  

i know this is a little off subject, but on both of my jeeps that i have owned (an 00 tj and 05 tj) both with 4.0s at idle never have ran very smooth, its like they will buck every 2 or 3 seconds and just are rough at idle, what is that from, is it the plugs(in my 05 they are stock and have 17k on them) or what is it that needs to be done to make it run smoother which i would imagine would help the overall effeciency of the vehicle?  

for the record its a 91 so im running the 39psi which im to understand is even a little "lean" for the stock engine. sry if i seem a little slow with this but im to understand what your saying is so long as im running the right sized injectors for the amount of psi comming out of the regulator (80% duty cycle)to feed the amount of HP im producing then it should be right at if it were a stock engine would flow so i shouldnt need to use either or but if it was running a little rich or lean then youd say to just use the adjustable MAP to incress the pulse in stead of trying to use the adj fuel pres reg to incress the duty cycle? but ideally i should bring it to a dyno shop so they can make a programmer to fix everything thru the whole rpm range at all loads.  

There is a term called STOICH. For gasoline fuel, the stoichiometric air/fuel mixture is approximately 14.7 times the mass of air to fuel. Any mixture less than 14.7 to 1 is considered to be a rich mixture, any more than 14.7 to 1 is a lean mixture.

The ECM uses the O2 sensors to determine if stoich has been met. If not, the ECM uses various input sensors to aid in the look-up of a fuel map that would obtain stoich.

The map sensor is capable of determining altitude. Higher altitude needs a richer mixture.

Higher fuel pressure will deliver slightly more fuel for the same injector pulse width.

So, they both do the same thing in different ways, richen the mixture.

The reason I say they are goofy is because it's like changing the scale on a thermometer. The mercury still has the same volume at a given temp, you just read it differently. But, if you actually cared about the volume of mercury at a given temp, then the scale is not really important. The mercury represents air, and the map sensor is responsible for reading the air.

Done right, the injector size would be correctly calculated and the fuel maps would be the controlling factor for tuning, both in terms of power and emissions.

But, that is also the most expensive. So, in order to save some bucks you have mechanical fixes as opossed to software fixes.

Just remember, if you try to richen the mixture the ECM just might be fighting you in the opposite direction because of trying to maintain stoich.

The ECM also might be determining that stoich has not been met when it has because of variables that have changed.

That's why I think you want a programmer.  

thanks you, a very informed answer.