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CAS sensor problem

Dev RB25

By Dev RB25,
in R Series (R30, R31, R32, R33, R34)

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Dev RB25 Explorer

Dev RB25

Posted
Posted
CAS sensor problem

Hi guys,

Advance timing = anti clockwise rotation on cas = higher timing value on pfc

Retard = clockwise = lower timing value

Right?

The issue is, my pfc reads lower timing when i advance , and higher value when i retard.

Will this point out to a faulty CAS or wiring between the 2 signal wires swapped around ?

my mechanic recently did an FFP upgrade and he messed around with some of the wirings, because he wanted to tidy up the engine bay.

Hoping if any can shed some light if its a simple as just swapping the wires or should i replace the cas?

 

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https://www.sau.com.au/forums/topic/467907-cas-sensor-problem/
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Dev RB25 Explorer

Dev RB25

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Posted (edited)

yea is starts fine. just troubleshooting a weird high rpm misfire. but i finally got arround to figuring this cam timing vs crank timing .

Advance timing = anti clockwise rotation
Retard = clockwise

applies to cam timing

Advance timing = clockwise rotation
Retard = anti clockwise

is for crank.

the cas is a crank angle sensor mounted onto the cam. therefore advance is clockwise.

and i just learn that the service manual says advance -

 

Quote

Because the further before tdc the spark plug fires the more advanced it is as its occurring earlyer on in the cycle

 

Edited by Dev RB25
Ed.williams5 Enthusiast

Ed.williams5

Posted
Posted

High rpm misfire first place I would go to is plugs. Then to coil packs and ignitor if that didn't fix it. 

When you get the high rpm misfire is it only WOT or are you able to Rev past at partial throttle with no issue?

  • 2 weeks later...
Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

also moving the cas does not change the timing on the PowerFC..

you need to sync what the PowerFC is telling the car to do... playing around with the CAS blinding will result in this scenario:

  • PowerFC tells motor 15
  • Motor is actually at 25
  • Go on boost, and blow motor because you're 10 degrees more than what you're supposed to be at

Yes, you will now say "but the PowerFC numbers are changing as I play with the CAS" - that is correct as you play with the cas your motor behaves differently and then jumps into a different cell which may have a timing value of 20 degrees.. that is what you're reading.

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