Tuning my AFC.

[BGuinard]

Hey all, I am new to the DSM world and I bought a 95 Talon with some mods already done. First of all let me start by saying the car is automatic. It has a 14b ported turbo and mani, 3 inch turbo back exhaust, FMIC, GM MAF(t), AEM Wide-band o2 guage, apexi SAFC-II.

Anyway I need to tune the car, It stalls immediately and wont even idle briefly. Also at full throttle I hit fuel cut off.


Can anyone help me?

 

[DSMDriver69]

This may put you in the right direction for the afc. RRE's Super AFC Setting and Adjustment Tips . About the fuel cut your probably getting it because your injectors/fuel pump are two small. Are they stock and how much boost are you running?

 

[delta448]

If you're using stock injectors, the airflow signal will not be offset enough to keep you from hitting fuel cut at the same amount of airflow as a stock 2G. What size are the injectors?

What SAFC settings are you using?
SAFC set up for Karmen MAF?
MAFT in blow through?

 

[918dsm]

this helped for me but i also have a gm maf and it doesnt really explain how to tune with it but it does give you a general idea.

 

[Killa_dsm]

Also you should look into getting a logger. These links should help get you started on tuning the S-afc. http://www.dsmtuners.com/forums/art...c-mid-point-correction-factors-operation.html
http://www.dsmtuners.com/forums/articles-tuning-ecu/58403-definitive-piggyback-tuning-guide.html

 

[JayRolla]

The ecu doesn't care what size injectors u have when cutting the fuel. It happens when the maf is over run which the 2g can easily run 30 psi on a 16g. It has to be cutting due too a major boost leak. If u have stock injectors set all settings to zero on safc. If it's still stalling u have another issue like a major boost leak.

 

[delta448]

The ecu doesn't care what size injectors u have when cutting the fuel. It happens when the maf is over run which the 2g can easily run 30 psi on a 16g. It has to be cutting due too a major boost leak. If u have stock injectors set all settings to zero on safc. If it's still stalling u have another issue like a major boost leak.

Just to add:

The ECU cuts fuel at 2.5 grams per engine revolution of airflow. If you have larger than stock injectors, you will have to adjust the reported airflow to the ECU with your SAFC in order to deliver the proper lower pulsewidth for the higher flowing injectors. Doing this adjustment to the reported airflow means you will pass 2.5 grams/rev by the amount you are offsetting the signal before you hit fuel cut. On a 14b, it takes a fair amount of boost to hit fuel cut even on stock injectors. If you have zero'd out the SAFC on stock injectors, it should start and idle as if the SAFC wasn't even there. Pressure test the intake tract.