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2G How to test 1g CAS?

Colt4G63 also

Proven Member
3,393
51
Jul 23, 2008
Tonawanda, New_York
Hope you guys don't mind me jumping in on this. I was about to start a thread on this very thing and figured this was appropriate and not considered hijacking:D

I'm just finishing up a complete rebuild and inregard to the CAS, I did what was said about setting the tab/notch in alignment and making sure the #1 was a TDC, but as far as any manuals I've read and anything I can find using search, what else is there to do once this is installed like in post #6.

Am I to assume as long as I set the CAS properly and the #1 is TDC, then I just tighten the bolts up and call it good:confused: At what point in the process would I have to adjust the CAS? I read that if the timing is grounded and you set you timing light for 5*BTDC, you don't have to adjust the CAS if your timing is correctly showing, ONLY if the marks don't line up at 5* mark..am I correct or missing something.

Thanks for the help.

Yeah that's right, you fine tune the spark timming by turning the CAS while pointing a timing light at the harmonic balancer when the vehicle is running, and the timming connector is grounded.

I assumed that you would just tighten the bolts up, but now I'm second guessing myself. you could be right, but I have no idea. Wish I could be of more help :confused:

I installed a new CAS yesterday, and still have no spark. I've used the multimeter on the CAS, the power transistor, and coil pack. Does anyone have a diagram of the ignition system from the coil pack all the way back?

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Hope that's enough. If you need the pinout diagrams let me know.

Ps. "L" means blue.
 
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SubversionX

Proven Member
241
7
Jan 8, 2010
Virginia Beach, Virginia
Thank you for the diagrams, they were very helpful! I started tracing wires, and taking off the electrical tape that the prior owner wound a million times around them. Turns out, that two of the four wires to the CAS, had been twisty tied and came apart... so... I'm off to figure out where they connected to. Thanks for all your help guys!
 

SubversionX

Proven Member
241
7
Jan 8, 2010
Virginia Beach, Virginia
Right, I suppose I worded this wrong. Where does the other side from the CAS lead to? I know that it's the TDC sensor, but I'm not sure where the other end goes to? The ECU?

Also, I found a good picture of the ECU and exactly which pins go to which harnesses, but I can't find it now. Does anyone have an idea of where I can find it?

On another note, while looking through the Haynes manual, it says that it's the Camshaft Position Sensor (CPS)... Not that this really makes a difference, just mentioning that I believe that CAS and CPS are extremely interchangeable acronyms.

Special thanks out to you Gofer, you've been extremely helpful. I'd be totally lost at this point without your help!!!
 

Colt4G63 also

Proven Member
3,393
51
Jul 23, 2008
Tonawanda, New_York
SubversionX said:
Hey, it's me again. Are you saying that the "TDC" wire should be connected to pin 89? The other one is the "Cam" wire, and is connected to pin 88? Sorry, I'm a little confused about how the CAS works, I suppose.

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SubversionX

Proven Member
241
7
Jan 8, 2010
Virginia Beach, Virginia
I have a new issue now; I'm not reading 12VDC from the ECU out? When I take the harnesses off, I get 5vdc, but then nothing when I reconnect them. Help?! :'(
 

DosoGSX

Proven Member
74
1
Jul 5, 2010
Houston, Texas
I am having a problem with my car dying a couple seconds after starting and was suspecting the CAS. It is a green top CAS in my 6 bolt swapped 2g. I performed the test as instructed and show 5v on the white wire when I spin it but not on the yellow wire.
I went ahead and ordered another CAS and also tested another I had on a spare head and neither of them are showing anything on the yellow wire while the white is still giving me a 5v reading when spun.
Am I doing something wrong, or do I need to take a voltage test at the ecu pin for the CAS? I figured if I'm not getting 5v at the CAS pigtail, I'm not going to be getting anything at the ecu plugs. Maybe I am just having bad luck with the sensors and keep grabbing bad ones.
 

kmetiuk

Proven Member
521
124
Mar 10, 2010
Edmonton, AB_Canada
Moving thread to the Electrical Tech forum, where it should have been posted in the first place.

You'v got your acronyms backwards, the CPS (CRANK position sensor) and the CAS (CAM angle sensor). The reason why your CAS has (4) wires going to it is because its a 1g CAS, not a 2g like you were probably searching for.

Your CAS has four wires going to it, a 12v signal and ground the other two are signal wires for the TDC and CAM inputs to the ECU. To test them you'll have to pull the CAS off the head and turn it by hand, this will allow you to test the signals with a multimeter as you spin it. Both the CAM and TDC signal wires should read up to 5v as you spin the CAS, the CAM signal wire pulses 4 times per revolution and the TDC pulses 2 times.

Heres a pin out of the CAS connector going to the ECU so you can check continuity of the wires and know which wires to test for the CAM & TDC pulses.

ECU Pins to CAS connector Pins -
  • CAM Signal wire (YEL): Pin 2 at the CAS (4 pulses per revolution)
  • TDC signal wire (WHT): Pin 1 at the CAS (2 pulses per revolution)

When you pull the CAS off to test it you need to make sure you don't have it spun 180* out or else your motor won't start at all, heres what it SHOULD look like. The motor needs to be at TDC when installing it like this...

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:dsm:




Man I am struggling with this issue as well. I have gone though so so so many things and still my issue is unresolved. @gofer plz help me or anyone else really. I am fcuking stuuuuuumped.

I have swapped 2 sets of coils, 3 ECU's, 2 PTU's,and 2 different 1G CAS (1 metal top and 1 black top). Issue is always the same no matter what combo of components.

I spin the CAS by hand and I get the spark only out of 1 coil. I checked the Ohms on the coil and they are good.


That 1 coil sparks 4 times per revolution of the CAS which I find weird. I put a mechanics stethoscope on the injectors and I think they are all firing but tpugh to say b/c its faint and they are all so close to each other. I also put the multimeter on the injectors and I can see it moving as well so I am pretty sure all 4 injectors are firing as well.

When I measure the CAS plug not connected to the car's harness but uplugged from the CAS I get:

12V across pins 3 and 4.
5V across pin 2 and 4 (yellow)
0.8V across pin1 and 4 (white)

I think the issue is pin 1. For some reason the ECU is not pulling pin1
 

1990TSIAWDTALON

Moderator
9,011
4,887
Nov 14, 2013
Independence, Kansas
Checked continuity between the pin 1 on the CAS and the ECU pin? Its about the only thing to do, then start looking back inside the ECU if that tests good. Swapped coils around to watch it follow the coil?
 
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