Why does the PERCENTAGE reading on the SAFC only read to approx 85percent when the vane is full open??? But read virtualy zero (.4 percent) when the vane is full close????

 

thats a good question, i was wondering that myself. is it different when dealing with the TII's from the NA's?

 

This one I speak of is on a 86 non-turbo. My turbo car does not have the tps signal sent to it's SAFC....because I'm using the signal from the boost sensor instead, on that car.

If I had the turbo car's safc attached to the tps it would do the same thing as I described for the non-turbo. I've no doubts about that because I've been playing around with putting a spare turbo afm on the non-turbo (not for more pwr etc, just circumstances that I won't go into).

 

what is the voltage output of the AFM? the S-afc is probably looking for a 0-5 or 0-1 and maybe the AFM can't produce that much.... or loss from old wiring...

never tryed pushing mine in all the way and reading.


or is the AFM a pot. which changes resistance and it reads current changes??....

 

what percentage are you refering to the throttle or air flow?

 

airflow

 

With the key to ON, the voltage is approx 4volts. Then you start the engine, and the voltage is supposed to be b/t 2.5 to 3.5 volts. When you are really on the throttle the voltage should drop waaayyyy down. I just don't remember the exact figures at idle right now. I'll look later and see what they are at full tilt also.

Nope, not talking tps, talking about the vane in the air flow meter and how the SAFC has a monitor where you can ....monitor the percentage of airflow. I was expecting zero to 100 percent. Ain't so.

I even turned the key to ON, held the vane full open for a full minute to give the safc a chance to see the full voltage value of the afm.

Whether I watch the turbo car or the nonturbo car, neither will show more than approx 85 percent at full tilt OR having their vane held wide open by hand and watching the safc monitor.

 

Oh, darn. It's probably because the voltage does not drop to zero when the vane is full open. I shoulda taken a look when I pushed the vane full open with my hand. Oh well, tomorrow I'll look again.