Factory Fuel/Air Ratio's
 

I have an '86 GXL with a '91 motor in it and a SAFC II to tune it with. Now up to this point i haven't really fiddled to much with the SAFC II but just to be safe i"m wondering what the factory air/fuel ratio is for my current motor. I believe the factory TII's were 11/1 but that's not going to help me since i'm n/a. Thanks in advance

no idea. but i can tell you its VERY VERY RICH. you can put in a -15 correction for crusing (closed loop) and be safe. WOT I would adjust without a Wide band

The ECU varies the fuel all over the place depending on air flow, temp, throttle, & pressure sensors.
There is even a idle lean down after 90 seconds idling.
The S-AFC biases air flow, but the others still actively adjusting fuel.

A wideband is best, but even a cheap AFR gauge will help.

Only on S5 engines and that is for if the engine is warm on curtain condition and if the engnie is cold. Its controlled by the FPR and a 12v 3 way valve. I would HIGHLY reccomend removing the 3 way valve and connecting the FPR directly to the intake manifold to eliminate startup problem and usless fuel being delivered

I would only use WB to adjust the SAFC

interesting...now if only i had the money to spare for a wideband sensor :mad:

you can however adjust the idle and cruise. I took about -7 away for my crusing (LOW THRTL) and about -5 for idle. . I did this by ear so i cant tell you what my AFR was at. I should wouldnt adjust your HIGH without a wideband.

btw. i got 16-17mpg after i put on the afc and tunning it by ear. Before i got about 13 or so. And now im back down to 13 since mine got stolen :(

The fuel pump resistor circuit is also called in.