bigger injectors and fuel pump

[aaronr]

Well replaced the injector with 42's and put a waldo 255 pump . I'm wounding if just need to redo my V.E table and short fuel trims were +35% when a/f came back around 15 then when rev up the trim go back to +5% and the a/f goes to 19.1 and works way back to 35% on the short fuel trims. I'm thinking I should redo my v.e table for the bigger injector. I'm running co3 sem-closed looped and changed my fuel rate already. 58 psi with no vacuum and 50 psi with vacuum.

[nevinsb]

I would question whether the injector flow rate was calculated correctly if it was running fine before the injectors were replaced. There is an injectors.xls file floating around the internet that I have found quite helpful. Otherwise it was possible that someone previously had tuned the PCM with incorrect. If this is the case, you will have to run through the auto-ve again.

Where'd you find the waldo pump?

[5.7ute]

Where'd you find the waldo pump?

It would help if you post your tune file.
I agree with nevinsb in regards to the IFR table being incorrect either before the change or for the current injectors.

[CoryF]

aaronr,
One time I was messing with my tune and I changed the Injector Flow Rates for a new racetronix fuel pump. When I did this it threw off my AFR.
One good thing about changing the IFR is that it was a constant value that gets adjusted. Once I changed it back to the flow rate that I wanted. I did a "short" AutoVE and then was able to use that data to tell the BEN factor that all the cells should have been off by. Then I changed the Main VE table with that factor for the daily driving cells (the ones that get 50+ hits during AutoVE). Then did a complete AutoVE so that I wasn't running around real rich/lean.

I don't know if that makes sense, I chopped it up a lot as I was typing. lol

I attached a excel spreadsheet that will help.

Excel spreadsheet --> USE THE ONE ATTACHED IN THE NEXT POST

-CoryF

[aaronr]

Here is my current tune.

[CoryF]

Excel spreadsheet --> USE THE ONE ATTACHED IN THE NEXT POST

Okay so I decided to make the spreadsheet a little easier to understand. Let me start off by saying that I did not make this entire spreadsheet, I got it from another member and added more parts to it to help adjust the MainVE table when you change the Injector Flow Rates.

The new spreadsheet is quite simple and is a lot like the last one.

-The first table you paste your BEN's into (the only place you should paste)
-The second table tells what percent rich/lean each cell was
-The third is the "smoothed" value that you should paste into your MainVE table
-The forth is "new" follow the directions and it will either be populated with:

1. The average BEN Factor from the first table
OR
2. A set value that the user has predetermined

I hope this helps you dial in your AFR with a new IFR. PM or post up if you have any questions.

NEW Excel Spreadsheet ---> VE_Interpolation_tables.xls

-CoryF

[CoryF]

Shouldn't the IFR table {B4001} should be a linear graph, not a constant value...

There is a Excel spreadsheet that you should do a search for that will give you the right values for that table based on your injectors. Just run a search for IFR spreadsheet.

-CoryF

[nevinsb]

I guess that would depend on the fuel pressure regulator too.

[CoryF]

The Excel sheet that I downloaded from somewhere you are able to change the fuel pressure for different Manifold pressures. From the factory the fuel pressure regulator should keep a constant fuel pressure that might fluctuate a little. If you are running a turbo car and have an adjustable fuel pressure regulator the graph would still be linear but would have a steeper slope.

-CoryF

[5.7ute]

If the 42lb injectors are rated at 3 bar(like I am pretty sure they are) Your ifr table is wrong. Since you are running a vac referenced regulator you should have a constant value of 6.1107 at 58psi fuel rail pressure.