A9P Tuning question

gt90stang · 09-18-2008, 12:11 PM

Hi,

Got a chance to do a little fine tuning and found that on early startup while in open loop my AFRs are 17:1 with the smog pump disabled. The high AFRs causes a little surging in idle.

As a fix I tried changing the Open Loop Fuel Multiplier vs ACT by putting 0.9 up to 102*F. This worked great and eliminated the surging.

The question is how to fix this correctly so there are no adverse interactions. Maybe with the Fuel Table Base Open Loop. I'm just nervous that the Open Loop Fuel Multiplier vs ACT may add fuel at WOT on cool days but is only 10% so wouldn't be the end of the world.

During closed loop and WOT the previous tune delivered accurate AFRs under all conditions so I don't really understand why it is running lean at startup until closed loop is reached. My Kamrfs are at 1.004 in closed loop.

Thanks, Don

09-18-2008, 12:11 PM	#1
gt90stang Member Join Date: Aug 2005 Posts: 72	A9P Tuning question Hi, Got a chance to do a little fine tuning and found that on early startup while in open loop my AFRs are 17:1 with the smog pump disabled. The high AFRs causes a little surging in idle. As a fix I tried changing the Open Loop Fuel Multiplier vs ACT by putting 0.9 up to 102*F. This worked great and eliminated the surging. The question is how to fix this correctly so there are no adverse interactions. Maybe with the Fuel Table Base Open Loop. I'm just nervous that the Open Loop Fuel Multiplier vs ACT may add fuel at WOT on cool days but is only 10% so wouldn't be the end of the world. During closed loop and WOT the previous tune delivered accurate AFRs under all conditions so I don't really understand why it is running lean at startup until closed loop is reached. My Kamrfs are at 1.004 in closed loop. Thanks, Don