The intent of this page will be to summarize my experiences and try to build some structure to the process of tuning.-by

It is not the intent of this page to provide step-by-step instructions, but rather to list the major items that need to be worked. 

By breaking tuning into stages, it should become easier to tackle.

Updated 12-20-06

Stage I

Here is a summary of some of the first changes that need to be made when starting out with the TwEECer.  After performing these changes it would be a good idea to do some data logging and verify that KAMRF 1 & 2 are not too far off from 1.00.  The EEC-IV seems to have a maximum adaptive ability of 12%.  If you are getting readings of 1.12X or .88X, then you have maxed out the ability of the computer to make changes with the KAMRFs.  Once you have made these changes move on to Stage 2.

Hardware/Hard Tune Changes
1. Set Base Timing to 10*
2. Set Fuel pressure to 38-39psi, or install stock regulator
3. Set Base Idle (make contact with idle screw, then turn 1/2 turn more) 
4. Verify the tps is within range, between .8 and 1.1 should be fine

5. Pull your diagnostic codes, and perform a general tune up.  Any hardware problems must be corrected before attempting to tune the computer.

TwEECer Changes
1.Turn off EGR function (If system has been removed)

2. Disable Thermactor Control (If system has been removed)

3. Set idle using CalEdit (between 650-900rpm depending on cam)
4. Change MAF Transfer (download if available)

5. Change Injector High/Low Slopes per TwEECer Manual

6. Change CID scalar (if applicable)
7. Change/Verify MAF min/max voltage (0v, 5v)

8. Change Adaptive Update Rate values to either 3 or 10.  All values except the bottom 2 rows can be changed.  You don’t want to change closed throttle idle positions as it will cause problems on deceleration.

Stage II

(this section is still being revised)

Now it is time to start making changes to the Fuel Injector Settings.  Here is a list of what should be done.  It is suggested that the below order be followed, but all situations will be different.   

1. Throttle Body Airflow
2. ISC Valve Duty Cycle
3. Battery Voltage vs. Injector Offset (vBat)
4. Injector Slopes
5. Injector Breakpoint
6. Injector Timing

It will be assumed that the reader is using EECAnalyzer, due to how easy EA is to use, and how relatively inexpensive the program is.

1. Throttle Body Airflow

This step will give the computer accurate data to use in regard to the airflow through Throttle Body when a larger Throttle Body has been installed.

2. ISC Duty Cycle

This should be a quick check if all is well.

3.  Battery Voltage vs. Injector Offset (vBat)

This is a fairly simple process when using EEC Analyzer.  Basically, you will datalog while running the car at various conditions, and various charging system loads. 

Be sure to datalog the following conditions; full charge cruising (with no/little electrical load), idle at low e- load, idle at medium e- load, idle at full e- load, and idle at medium and full loads with the alternator un-hooked.  Un-hooking the alternator will provide accurate data points for very low voltages, which is valuable even if you never hit that low of a voltage.  This should provide a broad range of battery voltages for EA to use.  Be sure to select Battery Voltage, Injector PW1 & PW2, and KAMRF1 & KAMRF2 in your Payload.  Then EA will use your datalog to make adjustments to the Voltage vs. Injector Offsets.  It may take several attempts to get this nailed down, as EA will make small adjustments each time.  When the new vBat numbers are not significantly different from the vBat contained in your .ccf file, you are done.

4.  Injector Slopes

This step is fairly straight forward as well. 

5.  Injector Breakpoint

The A9* strategies use the Function - Injector BreakPoint a little differently than other strategies. For most strategies the Inj BP is the point at which the computer switches between the Injector High Slope and Injector Low Slope, which makes sense.
The A9* however is slightly different in that, what is called the Injector BP is actually used as an Injector Pulse Width modifier, and the actual Injector BP is hard wired into the EEC as 2ms. When you make a change to the Function Inj BP in an A9* computer, you are actually changing how much fuel is cut from the Inj PW below 1,500rpm. The use of a larger number in the Inj PB Function will pull more fuel from the already calculated Pulse Width, from idle until 1,500rpm.

6.  Injector Timing

This step will make corrections for an aftermarket camshaft.  To get an idea of what EA is going to do read through the help file provided in the Cam Specs Tab of EA.  Be sure to datalog the following; PW1, PW2, LoadX, RPM, and vBat. 

There are some things to watch for in EA that will give erroneous results.  Watch the setting for Injector Timing (either start or stop), and the setting for Injector Firing Event.  The help button in EA will guide you through which buttons to select here.

There is a good Tip Sheet on EECTuning.org which will explain things in more detail... http://eectuning.org/index2.php

Check item 3 under 'Documentation'

7.  Ignition Timing

This step will maximize timing for specific driving conditions. 

Stage III