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Cas Sensor....may Have A Problem...

r33turb

By r33turb,
in Engines & Forced Induction

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r33turb Contributor

r33turb

Posted
Posted

Hey guys, me and my mate were working on my car, and whiel we were doing the timing, my mate dropped the cas sensor, just wondering what the likelyhood of it being f&^kt is now???...its was dropped on concrete, not broken or anything but i think thats not what breaks them...the car should be ready to crank tommorow, will it be obvious if the cas is dead?

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https://www.sau.com.au/forums/topic/202982-cas-sensormay-have-a-problem/
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SevenAngryPenguins Proficient

SevenAngryPenguins

Posted
Posted

cas only goes back on one way so impossible to stuff it up, you should check your timing when it goes back on, it should sit in about the middle of the sliding holes, whats tippex?

r33turb Contributor

r33turb

Posted
  • Author
Posted (edited)

Yeah its marked with tiped(or white ink), on both the cas, and on the back cover.....anyway, when i place the cas on the cover it just snaps into place so i dnt think i can go wrong, only concern is the spline in the middle of the cas revolves, and theres a halfmoon inside of it, does this have to be orientated in a certain way to match up with the exhaust cam?

p.s no one answered if my mate dropping the cas will have cause it to die....im hoping not!

Are CAS sensors interchangeable between the rb26, 25 motors etc...?

Is it true i can test my cas sensor to see if it still works....heres a guide from another forum....

'Take the CAS off leaving it pluged in then turn the key to the on position. Turn the CAS by hand and you sould here clicking of the injectors'

Edited by r33turb
Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted (edited)

ive got a rb26 cas running on my rb25 head so it should work ok.

The CAS does line up with the half moon in the cam, if you look in the cam you can see the other half of the moon and line up the CAS and re-fit it.

If its buggard it wont start :( simple.

Ive never seen anyone do that test of the CAS before, it would be interesting to try it though!

Yeah its marked with tiped(or white ink), on both the cas, and on the back cover.....anyway, when i place the cas on the cover it just snaps into place so i dnt think i can go wrong, only concern is the spline in the middle of the cas revolves, and theres a halfmoon inside of it, does this have to be orientated in a certain way to match up with the exhaust cam?

p.s no one answered if my mate dropping the cas will have cause it to die....im hoping not!

Are CAS sensors interchangeable between the rb26, 25 motors etc...?

Is it true i can test my cas sensor to see if it still works....heres a guide from another forum....

'Take the CAS off leaving it pluged in then turn the key to the on position. Turn the CAS by hand and you sould here clicking of the injectors'

Edited by Guilt-Toy
blind_elk Grand Master

blind_elk

Posted
Posted

The shaft of the CAS has to be in the correct orientation to mate with the half-moon key on the end of the exhaust cam.

I have run a RB25DET CAS in a RB20DET without any problems.

That test should confirm the CAS working correctly.

Guilt-Toy Grand Master

Guilt-Toy

Posted
Posted

yeah change it over, make sure you mark with a white marker or liquid paper the position the CAS is so you can keep the same timing when putting it back.

Dropping it shouldnt hurt it that bad, unless you smashed it to the ground. Thats not to say that its going to last for ever if it does still work, if it works id buy a new one and keep it in the boot in case it decides to die so you dont get stuck.

Hey, thanks mate, how much is a replacement cas set me back?, and is it possible to break a cas sensor by dropping it?.....im getting anxious now.....

is it easy to test another cas from another rb26 easily enough to confirm?

nsta Mentor

nsta

Posted
Posted

Thanks all, the cas already has white markings on to line up timing, so it should be all good, from what i gather, there will be a half moon on the exhaust cam side of things as well, and the spline will only KEY in one way so i want have any issues there aswell....

Well what happened is my mate dropped it, it fell on my front bumper, then dropped onto concrete, it didnt crack in any way or get smashed up, just dropped i guess...

R31 Gagz Collaborator

R31 Gagz

Posted
Posted

Hey R33Turb,

If you find that you have to keep advancing the timing on the CAS to "keep the tune" or make it run good, then it most likely it is on the way out.

RB25 ones do work on RB26 engines, had one on mine but must have come off a motor with a lot of kms on it as it was half dead and fully advanced trying to chase the tune. The car would still start and seemed to run fine but on a dyno you could actually see the power curve spiking and dipping in the rev range that the CAS looked after, once it was in that range it couldnt read accurately what rpm the engine was at and was basically "estimating" the rpm.

Put a new CAS on and power went straight up 40rwkw and the power curve was nice and smooth again. Couple more hours on the dyno saw another 20-30rwkw with a lot nicer power curve again and about a 15rwkw gain across the whole range with about 65rwkw extra on the top end where the CAS was stuffing up.

So if you think yours is a bit sus, it could pay to get it checked out or even just try another good condition one on it and see if theres any difference.

Hope that helped :)

Cheers!

Gagz

nsta Mentor

nsta

Posted
Posted

Cheers dude - i want to get my car up and running, as i just replaced a headgasket on my gtr, so im hoping the cas is still in working condition for the time being, i will however keep an eye out for ojne and replace immediately if i notice its on its way out.....

everything else is spot on so far....only about 2, maybe 3 more hours of labour to go and the car should turn over...fingers crossed:)

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