Jump to content
SAU Community

Recommended Posts

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?

Link to comment
https://www.sau.com.au/forums/topic/202982-cas-sensormay-have-a-problem/
Share on other sites

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?

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

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

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.

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?

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...

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

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:)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Mate you saved be from dying in the Perth summer. AC wasn't changing direction and just going into diagnostics mode fixed it. You're a legend and I would shout you a beer if I could!
    • Unfortunately effort gone to waste, you will have substantial issues with how the manifold and wastegate have been integrated. You would be so much better off with a modified stock manifold like this: https://hypergearturbos.com/product/rb25detexgatedmanifold/   OR literally just getting a off the shelf Sinco or 6Boost manifold as myself and others have mentioned.  
    • Yuck. But it's kinda the same principle, moving timing around to make car run bad but sound good.... I went for a more spirited tuning drive to iron out a few things. Car no longer stalls, and it loved to dip RPM low when you clutch in. After tuning this (and the 4-5 tables that HPTuners/LS1 OEM ECU wants for idle air correction) it's now behaving somewhat normal. All expected because there's a new TB, new Intake manifold and that new TB which is 102mm vs 78... has an entirely different IAC passage which is smaller because ????? Unfortunately at this point I went to make further fine tuning changes to avoid it flaring up, you know... _tuning_ the HPTuners dongle died. Well to be more accurate - The USB cable died in a fashion that anyone who has ever charged a phone will recognize. After the app demanding I resync it 50 or so times (which all 'succeeded' but all failed) the device does not want to sync and I've logged a ticket with support to see if it's fixable. US Support said it was a 'storage issue' but after removing the SD card inside it and formatting it/fixing it the issue does persist. Unfortunately usually the fix is "Turn in your old dongle and pay $700 for the upgraded one" it's cheaper because I get some free licence credits I unfortunately don't need. However I'm 10 minutes down the road from HP Tuners AUS/VCM so at least I won't need to post it, and logged a new ticket for support over here. Definitely drives different. My SOTP dyno believes it's probably making 310-320kw instead of the 280 before.  It scrambles for traction a little now whereas it previously different. It drives like a bigger cam car up top even though the cam is smaller, likely due to the cam not being advanced 6 degrees. The timing is deliberately low and the fuel is very rich so who knows if this will improve on the dyno. It may, imperceptably. Also funny is removing the pineapples definitely makes the car squat more and axle tramp less. So this behavior of having more top end, squatting more, and scrabbling for traction more makes me think = more power. But I could have just been sitting on the threshold of that kind of behavior before. Time will tell if my butt dyno is calibrated right. I need the exhaust leaks fixed before dyno tune for obvious AFR related reasons - I repositioned the pipes but I'm not confident it's fully sealed even if it is better. At least the car does drive around while I cannot tweak/tune it for now. And I have aircon again. medium success!
    • Don't use that manifold. Please don't use that manifold. Sunk cost fallacy is not worth the later pain. None of these will be relevant to the change that will come from the different turbo and manifold. As in, the effect of the exhaust will be nil, regardless of what else is changed. And all the cam and fuel system stuff is not changing either way, so has no effect. The turbo and manifold (and to a small extent the wastegate)....big change.
×
×
  • Create New...