so how many diff ways can you alter fuel with the PFC

injector screen:

you can set sizes, delays

injector map:

it seems to have two axis, one for RPM, one for pressure...

question is, what are the pressure figures? 24000 is the max, what is 24000 (in units of measurement?)

do you ever alter this section?

PIM voltage:

you can set percentages for RPMs....does this control basic fuel injection?

meaning, if i see my wideband readout, and i'm running lean from 4500rpms up, can i just go 100%+ in these areas to make those parts richer? is it just for WOT?

how do you richen up certain areas of your RPM band on WOT? why isnt' this thing as user friendly as the S-AFC?

 

Good questions all. I just installed my PFC and plan on the wideband next. It would be a huge help if someone with the knowledge to would scrap the crappy instruction manual and write a good one.

Tom

 

Yeah, that would be awesome if someone had the time. And make it sticky. It seems that most of the questions are answered somewhere on this forum, but doing the right searches to find the good info takes forever. I'll be getting a wideband soon myself, and I'm starting to run into these questions...like how the hell do you EVER get all the non WOT cells correct....

 

You've asked this question in two different threads. Now, I know you're just trying to learn like the rest of us, but do a little research first. You can find your answer in the manual on page 20 (bottom of the page, on the left).

 

okay, so you're my mother now?

i think my question is very valid and unless you plan to answer it....go post somewhere else

 

I shouldn't even respond to your immature post, but since you're too lazy to read the damn manual I'll hold your hand...

What is a Pressure Value?

If the pressure value is [20000], it is equal to 2.0 kg/cm2 of absolute pressure. Atmospheric pressure is about [10000] of pressure value.

 

With just the commander, you can add or subtract fuel (not changing the injector sizes) using the PIM voltage based on RPMS or Map sensor voltage. Both are universal so if you have time, it best to try and make changes in the fuel correction map. And that is the 3rd way with the commander, in the fuel correction map....cell by cell to the ones you are trying to tune, not necessarily every cell.

If your lean fron 4500 up, you'd want to atleast add fuel in the PIM RPM page
to 102% so that it adds fuel in those rpm ranges. You could also add fuel using the map sensor voltage adjustment. If you know the voltage of when your at 4500 rpms and see what voltage is at that rpm, you could then add fuel so that it only adds fuel when your under boost. If your lean, up the value over 100%, if you were rich as hell, you'd lower it under 100%.

Look for the e-mail soon, I kept getting knocked off line with all the bad weather lately, not to mention me just hanging up and shutting down when the lightning hit a house up in our subdivision.

Tim

 

That's funny as the manual does a fair job of describing all of this and even more.

P20 abs pressure values per row.
P21-22 for fuel correction.
P24 PIM fuel by voltage and by rpm.
P25-26 injector size and lag.
P29 acceleration fuel.
P30 temperary fuel correction.
P31 fuel by water temp.
P32 cranking fuel.
P33 deceleration fuel cut.
P37 O2 control.

You can learn so much by comprehensive reading.
Try it sometime!

 

eh, my apologies

the physical copy of the manual i received seems to be missing several pages, i now have the PDF printed out, it's much easier

thanks for the information

 

Glad everyone's playing nice now....

I personally understand HOW to change things, just lack a good solid grasp on tuning, I suppose. I understand the basics...you get on a dyno, make a WOT run, and then adjust the associated cells accordingly. But then do you just guess and blend the cells around it? Do you do non-WOT runs? Ultimately I want to hard mount a wideband, so do you just keep making runs trying to hit each cell at varying throttle? Seems like it would be very possible to have good WOT cells but have a dangerously lean spot somewhere else.

Then timing is a whole new beast. I'm used to 70's piston cars where you twist the distributor till you hear the pinging and then back off a hair!

Maybe there's a good resource out there that someone can recommend? I don't mind reading, but unfortunately recently I haven't had the time to sift through all the marginal posts to find the good ones.

 

Ok, I read all that in the manual. Three times or more. Now, with all those places to add or subtract fuel, which one is actually controlling fuel. And or what determines that.

Tom

 

They all control fuel! Some for startup, some for cold water temp driveability, some for initial acceleration, some by boost, and some by rpm. The title/description
tells you that!

The temporary and PIM changes are for quick and dirty
across the board(cells) changes. But the PIM changes can be left in permanently. After getting everything in the ball park, then make the same changes to the related fuel cells.

With a datalogit, the fuel correction map can be RECALCULATED into the injector base map.

 

under water temp correction, what exactly are the light/heavy loads and what do the numbers represent? percentages?

 

I see that on page 31 , but it does not really say. Another good explanation! I still say the manual is very vague and leaves a lot to be desired.

Back to my question: OK they all control fuel, so when the water temp is low, the computer knows this, and runs off the water temp correction numbers? You can't tell me you can pick that up by reading through that manual.

Tom

 

I did. And I am STOOPID, too.

I think of a set of settings or "a map of behvior (for fuel and spark)" with specfic parameters. Ambient air 30C, water temp 85C, etc.

Let's call that a "state." Now if you still want the car to run "the same" (let's assume it runs at a target AFR), you're going to need a seperate state that encompasses the changed parameters(ie. the new state is at 15C ambient air, and water temp of 80C).

So, with each variation of the parameters you have another map. Wow, that would take alot of memory and processing.

Instead you have a "base" or baseline and as the parameters vary from those in the baseline, adjustments or "corrections" are made. So think of it in terms of an equation with variables/parameters.

 

Hehehe. Chuckled when I read your first sentence. I think it was the inflection of your voice with the capitalization of STOOPID.

Ok I understand the 'baseline' description. If all is running well at basline adjustments are made to it as parameters change. How do I know what the basline water temp is? In other words, where is the info on the base map? I probably can't see things like water temp and ambient air temp for the base map, right?

Thanks for your help Tony. Will you pm me your number? I won't bug you much.

Tom

 

Tom,

We'll talk tonight.

To tell you the truth, I don't remember what the "base maps" details are in terms of expected values for the parameters. I have it somewhere.

Tony

 

talk tonight? talk on here so we can all learn

that's why i started this thread!

 

Thanks Tony.

If I learn anything I'll post it here. Honest.


Tom