2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

CAS and timing

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Old Mar 24, 2008 | 11:41 PM
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CAS and timing

I think i've gotten almost all my issues with my 87 t2 worked out and I want to double check the timing to make sure it's spot on for the factory settings. The p/o installed a new CAS himself and I have a feeling he didn't do it right.

Just to make sure I do it right all I need to do to restab the CAS is remove the blind cap and pull out the gear assembly line up the marks on bottom gear and shaft line it up with 5 degrees btdc mark on motor then when reinstalling the cas making sure the two points on the top gear are just starting to go into the black boxes. Just like in the picture (note: not my car in the picture). You don't have to remove that whole housing in order to reset the timing right?

Once you get that all done do you really have to hookup a timing light and mess with it any more or does restabbing it get it close to factory settings?

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Old Mar 25, 2008 | 09:08 AM
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You're not pulling out any gear assembly...

Rotate the engine until the first timing mark lines up.

Pull the cover from the CAS.

Remove the CAS.

Turn it so the notch on the bottom of the CAS shaft lines up with the dimple in the gear.

Hold the trigger wheel with your thumb so it doesn't skip around.

Install CAS. You may have to turn the body slightly to get it in place.

The end result should show the trigger wheels in the above position.
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Old Mar 25, 2008 | 08:06 PM
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so the big metal piece the blind cap screws into you don't have to take that out correct?
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Old Mar 25, 2008 | 08:17 PM
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Take the entire CAS out of the front cover. Line up the main pulley marks, then line up the CAS marks and stab it.

Does the car run? If so, why not just check the timing with an inductive light if you suspect it is off? You'll need to do this anyways after a re-stab.
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Old Mar 25, 2008 | 08:26 PM
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I don't have a timing light yet. And it doesn't start almost every time I've tried. I got it fired up once and let it idle while we were refilling the coolant but after it started warming up it started idling crappy and then died. It hasn't started up since then. I let it cool back off but still nothing.
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Old Mar 25, 2008 | 11:01 PM
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It should trigger the light while cranking, so it doesn't have to run to check timing.

You can probably find a used one for cheap.
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Old Mar 26, 2008 | 04:38 AM
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Originally Posted by alexdimen
It should trigger the light while cranking, so it doesn't have to run to check timing.

You can probably find a used one for cheap.

Sorry. The ECU advances the timing during START (cranking). See page 4-49 of the Fuel and Emissions of the Training Manual that is floating around out there on the world wide web (China excluded).

The thread owner NEEDS a timing light. Just a common 20 buck timing light. Not a fancy one. Just a plain Jane timing light. See the timing procedure in the local FSM.

Big Metal Piece with Blind Cap Screws ................puzzles me and others.

A CAS that has been installed per the FSM (dimples on the CAS aligned/pulley mark aligned) should end up looking like the attached jpg I stole off the web. The two *pointers* on top of the CAS should be cutting across the corners of the two black coils inside the CAS. THEN a timing light is used to finish the timing. BUT if installed as shown in the jpg, the timing will be within five or so degrees of the finished product, so the engine should be starting without any problem.
Attached Thumbnails CAS and timing-caspointers.jpg  

Last edited by HAILERS; Mar 26, 2008 at 04:57 AM.
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Old Mar 26, 2008 | 06:38 AM
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i guess i'll be picking up a timing light this weekend.

the thing I am talking about I highlighted in this picture


I just want to make sure that I don't have to disassemble half the motor to reset the timing
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Old Mar 26, 2008 | 07:18 AM
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If you're CLOSE, the motor should crank and start.
I'd say if you're within 20-degrees + or - is close enough.
It might not run nicely, but it should crank and start...
This is a good sign that you're close with the timing.

You don't need a timing gun to get the engine running.
If you're good, you can actually adjust the CAS by ear by listening how the engine sounds while idling.
Of course, a timing gun should be used to adjust to factory spec.


-Ted
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Old Mar 26, 2008 | 08:56 AM
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the CAS is just held in by one little nut. It's the one that holds it in place from sliding back and forth. remove that, and unplug the CAS and then it just pulls out. When stabbing back in the gears move a little. play with it a little and you should get it to look like the picture within a few tries. It's really no that big a deal. Also owning a timing light is a must. Fancy ones don't work....i.e. Snap on et...just a cheapo timing light....harbor freight. Good luck, and don't panic.
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Old Mar 26, 2008 | 11:49 AM
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Originally Posted by HAILERS
Sorry. The ECU advances the timing during START (cranking). See page 4-49 of the Fuel and Emissions of the Training Manual that is floating around out there on the world wide web (China excluded).
Sorry about that misleading info. I thought that may be the case, but figured it would be obvious to actually set it with the engine running.

In that case you could get a light with adjustable advance and set it to that value if it's listed in the FSM or known.
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Old Mar 26, 2008 | 05:07 PM
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Here is the CAS pulled out. Just undo the one 10mm wrench size bolt/nut and pull straight out. Pictures and install in the free, online FSM.

Timing has to be set with the engine fully HOT and the RPMS under 1100rpm. Preferably nearer to 750 rpm but as long as it's under 1000-1100 rpm it won't make any difference.

The ECU automatically advances the timing when the rpms are over something like 1200 or so rpm. Since the tachs are not that accurate make sure the rpms are under 1000 rpm. The real advance figure is in the online, free, Training manual.

When cranking/starting, the ECU advances the timing for Trail and Lead to both five degrees BTC. After it starts the timing goes to -5 and -20 (L/T) if the engine is hot.

You start a cold engine and the ECU makes the afr Rich til somewhere around 125* and 155* where the afr gets Leaner. Tone and speed of the engine will change when those figures are reached....most likely.
Attached Thumbnails CAS and timing-pulledcas.jpg  

Last edited by HAILERS; Mar 26, 2008 at 05:26 PM.
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Old Mar 27, 2008 | 08:18 PM
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pulled the blind cap off the cas after lining up the marks on the pulley. It was off HUGE like 90 degree huge. Reset it and then pulled all the plugs cleaned them off, put in fresh gas and then she started right up. It's got an oil leak where the oil line goes into the turbo. I suspect when the p/o replaced the turbo he didn't tighten the back bolt on that flange.

What's the best way to get at that flange without too much disassembly?
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Old Mar 28, 2008 | 06:19 AM
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I'm just gonna pull the ACV off to fix the oil leak. If the gasket leaks when I reinstall it I will deal with it and wait for my blockoff plates to arrive next week.
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Old Jun 21, 2012 | 05:27 PM
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Originally Posted by HAILERS
Sorry. The ECU advances the timing during START (cranking). See page 4-49 of the Fuel and Emissions of the Training Manual that is floating around out there on the world wide web (China excluded).

The thread owner NEEDS a timing light. Just a common 20 buck timing light. Not a fancy one. Just a plain Jane timing light. See the timing procedure in the local FSM.

Big Metal Piece with Blind Cap Screws ................puzzles me and others.

A CAS that has been installed per the FSM (dimples on the CAS aligned/pulley mark aligned) should end up looking like the attached jpg I stole off the web. The two *pointers* on top of the CAS should be cutting across the corners of the two black coils inside the CAS. THEN a timing light is used to finish the timing. BUT if installed as shown in the jpg, the timing will be within five or so degrees of the finished product, so the engine should be starting without any problem.
What is the best way to get accurate RPM's if my Dash tach is not working ?

Also is there something i have to Jumper durring this process ?
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Old Jun 21, 2012 | 06:11 PM
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Originally Posted by mattsdajam
What is the best way to get accurate RPM's if my Dash tach is not working ?

Also is there something i have to Jumper durring this process ?
There is a Black wire which dangles from each of the coils that connects to nothing. Jumper a wire from one Black wire to another and this will cause the tach to run off of the leading coil.
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Old Jun 21, 2012 | 08:39 PM
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Originally Posted by satch
There is a Black wire which dangles from each of the coils that connects to nothing. Jumper a wire from one Black wire to another and this will cause the tach to run off of the leading coil.
That's the best info I have had! I have been dying to figure out how many rpms my idle was running ! What about that green connecter ? Aren't I to jumper that when doing the timing ?
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Old Jun 21, 2012 | 08:51 PM
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Originally Posted by mattsdajam
That's the best info I have had! I have been dying to figure out how many rpms my idle was running ! What about that green connecter ? Aren't I to jumper that when doing the timing ?
Some will say it's necessary when using a timing gun, but if you're setting the timing by eye then no.
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Old Jun 21, 2012 | 08:52 PM
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Originally Posted by satch
Some will say it's necessary when using a timing gun, but if you're setting the timing by eye then no.
Excellent !
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Old Jun 23, 2012 | 06:05 PM
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Wow... simply wow.
My post is pointless but i dont care cuz it will make me feel better.

Setting a CAS is the EASIEST thing you guys. Why does it take so many people to explain the easiest procedure.

1. Line up pully mark
2. Pull CAS out with top cover off.
3. Line up dimples
4. Put back in and adjust to where the first picture shows.
5. Start car
6. ???????????
7. Profit


I have NEVER EVER EVER used a timing light on a NA Rx7. Its really not a big deal.

/thread
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Old Jun 23, 2012 | 07:18 PM
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Originally Posted by 86GXL
Wow... simply wow.
My post is pointless but i dont care cuz it will make me feel better.

Setting a CAS is the EASIEST thing you guys. Why does it take so many people to explain the easiest procedure.

1. Line up pully mark
2. Pull CAS out with top cover off.
3. Line up dimples
4. Put back in and adjust to where the first picture shows.
5. Start car
6. ???????????
7. Profit


I have NEVER EVER EVER used a timing light on a NA Rx7. Its really not a big deal.

/thread
i always use a light to double check, but i do know i can stab the CAS and have the timing +/- 1 degree without the light...
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Old Jun 24, 2012 | 12:15 PM
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Originally Posted by 86GXL
Wow... simply wow.
My post is pointless but i dont care cuz it will make me feel better.

Setting a CAS is the EASIEST thing you guys. Why does it take so many people to explain the easiest procedure.

1. Line up pully mark
2. Pull CAS out with top cover off.
3. Line up dimples
4. Put back in and adjust to where the first picture shows.
5. Start car
6. ???????????
7. Profit


I have NEVER EVER EVER used a timing light on a NA Rx7. Its really not a big deal.

/thread
so i followed the procedure to the t above, i have an aftermarket pulley because i have 4 white marks, anyways i put the needle right between 10btdc and 0 , lined up the nipple on the crank angle sensor reinstalled it checked the position after reinstall, turned the car over and BAM. it sounds fine above 2000 rpm but as soon as it drops below its glug glug glug glug Die... what did i do???
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Old Jun 24, 2012 | 07:23 PM
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Originally Posted by mattsdajam
so i followed the procedure to the t above, i have an aftermarket pulley because i have 4 white marks, anyways i put the needle right between 10btdc and 0 , lined up the nipple on the crank angle sensor reinstalled it checked the position after reinstall, turned the car over and BAM. it sounds fine above 2000 rpm but as soon as it drops below its glug glug glug glug Die... what did i do???
you lined up the dimple and the pointer on the CAS right?
The pointer is above the gear.

If you did this all correctly then you probably have some other problem.
Vacuum leak, TPS, Sensor somewhere,

Also with having an aftermarket pulley i would make sure you are at the factory setting unless you have reason to be otherwise.
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Old Jun 24, 2012 | 08:47 PM
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Originally Posted by mattsdajam
so i followed the procedure to the t above, i have an aftermarket pulley because i have 4 white marks, anyways i put the needle right between 10btdc and 0 , lined up the nipple on the crank angle sensor reinstalled it checked the position after reinstall, turned the car over and BAM. it sounds fine above 2000 rpm but as soon as it drops below its glug glug glug glug Die... what did i do???
Have tried adjusting the idle screw on top of the throttle body? If it's having a hard time holding idle it could be not getting enough air. Just a thought lol.
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Old Jun 24, 2012 | 10:29 PM
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Originally Posted by JakeMG
Have tried adjusting the idle screw on top of the throttle body? If it's having a hard time holding idle it could be not getting enough air. Just a thought lol.
he's setting timing not fuel.
and since that pulley is aftermarket who knows where the marks are.
If you feel you are in the right Vicinity timing wise,and the car is running fair,then for the Hell of it,Pull the CAS again and move it one Tooth..one way or the other,and see if that fixes your issue.
I know the front pulley has marks on it.But really at this point you have already used them and thought it was close to a stock setting.Well you are close...What I am suggesting is line up that pulley,same as you did before and stab the cas one tooth one way..test.
then Try the other way.
Try Timing the car without pulley marks!.That is a real Pain in the ***,But I did it!
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