2?'s Vehicle Speed Sensor and A/F Ratio....

[artrenee10]

1)Where is the VSS located on a digital dash car?

2) What should the a/f ratio be on the scanmaster at idle...0'2's are in the 750-875 range...BLM"s are pegged at 128...Just checking numbers....
Thanks
Steve Chambers

 

[Daniel Jost]

o2's look ok, what are you talking about pegged, 128 is neutral, meaning that there is no fuel trim going on, Eric's chips idle in open loop but still learn so it is right on. I think that the VSS is located under the hood by the firewall, in the speedo line, can't quite remember off hand.

,Dan

 

[turbofish38]

VSS on a digital dash is on the back of the speedo cluster just like the analogs.

 

[pacecarta]

af isnt A/F(air fuel ratio)
af on SM stand for air flow and is the amount of air measured in gm/sec moving through the mass air flow sensor (MAF)
af at idle with std chip should be 5-6
wot af flow depends on improvements to airflow in intake and exhaust and the boost you run at , generaly above 17psi af should be topped at 255 . if your car doesnt reach 255 its not nescescarily sign of a problem but you should be concerned if its not steady
in the case of rebuilt MAFs ive noticed a problem with them reading good at idle but they react slow to sudden changes on quick spooling cars and cause leaning out (low O2s) , also some of them fail to reach 255 on cars that should easily reach that limit

the VSS optic is at the back of the gauge held on with a small screw ,but if you follow the ribbon wire down to the VSS buffer (green box ) youll find it is located at the driverside rear of the radio taped to the wire harness.