When turning the car to the on position. the boost sensor shows about -500mmhg on the gauge.

Now if the boost sensor is defective (which I assume it is), would that cause timing issues?


Also, when connecting a timing light, sometimes the timing bounces around at idle (jumps back and forth a few degrees), doesnt matter whether the set coupler is connected or not. Bad CAS?
Thanks
-Ross

 

few moons ago... i think someone decoded the S4 TII ECU (reverse engineered it) try searching at teamfc3s.org/forum

This individual dispelled the myth that the ECU retartds timming based on boost pressure.

I woudl assume this is also true about the S5 TII eCU as well

 

IF you look in the fsm there is a specific checkout of the boost sensor to see if its any good.FUEL SECTION

Also look at the RELATIONSHIP CHART in the 89 FSM. I notice that the chart shows that the pressure sensor does indeed effect timing. Look for yourself if your a disbeliever. Page F1-76

 

As for just when it effects timing .......got me. Could be just at idle or during deceleration and no other time.