Includes both our CAS (cam angle sensor) that bolts to the stock distributor as well as the expansion harness that connects to the ECU and runs to the coil harness and CAS.User supplies coils and coil mounts. This expansion harness plugs into the ECU's expansion port, through the firewall, and to the engine. Remove the 12 mm bolt. Does not matter if the CAS gets rotated slightly since you have the ignition timing marked. Just need to be careful we dont slide the CAS out of the back of the head during this stage. If the CAS was leaking oil, it will probably be flat, hard, and well lubricated. Will need both hands and the pencil again for the next step. The 1991-1992 CAS uses two photodiode LEDs and slots cut into a single plate to produce voltage pulses as light passes through the slots, and can be adjusted to set basic ignition timing. The 1993+ sensors each use a flux screening plate and a Hall-effect switch to produce voltage pulses as the vanes interupt the magnetic flux, and cannot be.

• Ignition Casino Scam
• Ignition Casino Poker

CAS O-Ring Change

by Jim Creer

Note: This article includes photos of a 1.6l engine. Additional photos of a 1.8 provided by Phil Ethier

The objective here is to change the Cam Angle Sensor (CAS) O ring in about 10 minutes without removing the cam cover.A timing light is not needed.Have done 5 like this and found it works just as easily on both the 1.6 and 1.8 NA Miatas.Only variation is the CAS is on the back of the intake cam on the 1.6, and on the back of the exhaust cam on the 1.8.Both are just as easy to do.Started doing this around Y2K, after doing several others using by the book.If not comfortable trying it this way then please follow instructions in your manuals.

Have a spare CAS, so we can look at one to see what we are trying to do.The arrow points to the O Ring we will be replacing.The area in the box is the tip that rotates inside the rear of the cam.The elongated hole is for the bolt that holds the CAS in place.This bolt is loosened for the CAS to rotate when changing the ignition timing.

A different view shows the two little “tangs” at the end of the rotating tip.They are slightly off center.There is only one way it will fit, so no chance of it being 180’ out of phase after installation.Also note one end has a little groove running down the end, which is a bit clearer in the previous picture.The opposing tang has a little dot stamped near the end and no groove.Found some that did not have this dot and just a flat end.

The size of O Ring needed is 1/8” – 1 ½” x 1 3/4”.They run around 59 cents each at about any local auto parts store, or can get this little pack of 4 each for $1.79.As far as I can tell it is made from the same material as the Dealership replacement units.BUNA-N.If you are not sure of this, go ahead and get one from the Dealership.Expect to pay at least $6, even with some sort of discount.

Another option is a Viton ring, rated for higher temperatures.

To prep for removal, have unplugged the O2 sensor (1.6) and both plugs.I tucked them back out of the way so have some working space.Used a soft lead pencil to mark position of the CAS.When finished, will align the marks again so the ignition timing will not change.Will probably be some grime and oil on the unit, but the pencil will mark through it.

As a side note for those that frequently prefer to change ignition timing, scribe a timing gauge here for different ignition settings.Will only take a moment to change it later and no need for a timing light or engine to warm up.Just remember as the timing belt stretches with age, or belt is replaced, this extra gauge will probably not be accurate.

Remove the 12 mm bolt.Does not matter if the CAS gets rotated slightly since you have the ignition timing marked.Just need to be careful we don’t slide the CAS out of the back of the head during this stage.If the CAS was leaking oil, it will probably be flat, hard, and well lubricated.Will need both hands and the pencil again for the next step.

Dave let me use this picture of his 1.8 CAS bolt.Little different shape and has a longer bolt head.May not be able to get some ratchets behind the head, but a 12 mm box wrench works very well on either the 1.6 or 1.8.

Now for a bit of dexterity!Slide the CAS straight back toward the firewall.Do not twist it during removal and try to avoid hitting the tip on anything.When clear, lower the back and rotate the front upward.I made a second pencil mark to show orientation where the little tang fits inside the cam.If you disturb the end slightly, make your best correction guess and mark it anyway.At best will only be a few degrees off, but may take a few extra light pokes when installing it back together.Will be a bit clearer as we progress.In this instance, the position marked was not the tang with the groove.That should be easy to remember!

Used pocketknife to cut the old ring off, or when you pry up on it a little, it may shatter and fall behind the engine.Have a new ring handy to fumble in place.The barrel should have enough oil remaining for lubrication.If you need a little more oil to smear, just poke finger inside back of cam.Does not matter if the tip was rotated, since will need to orient it again prior to installing the CAS.Caution is needed at these stages that pencil marks are not erased.For the next step will line up our pencil marks, starting with the little tang on the tip, orient it with the cam and ignition timing pencil mark and slide it in back in place.

Note.Many instances it is difficult to remove the CAS from behind the head, but still easy enough to replace ring as shown.

If you see this little space on the barrel between the new O ring and yoke, that means the little tangs are not properly aligned with the cam.Back the CAS out slightly and rotate a hair.Try another poke.Repeat if needed until it slides in.If you try rotating the unit with pressure on the cam, will just be twisting the nose out of position and be at it for a long time!I have only hit one exactly with the first poke, but could expect about 3 to 5 little jabs.Most will be pending on how well you eyeballed both pencil marks.

In this position the new O ring is flush against the yoke.That means it is properly aligned inside the cam.The fatter new O ring will be a little harder to squeeze inside the yoke.It should have some oil on it, can push harder on it and twist the CAS around a bit until it snaps back in place.

Brings us back to this picture.Replace the bolt and ensure your first pencil mark is aligned prior to tightening.Now the ignition timing is back in the same setting before the CAS was removed.Plug the 3 plugs back in and go for a drive!Can also pat your self on the back for saving a $100 from having a Dealership do the job.Should also be able to do the job in about 10 minutes rather than dropping the Miata off somewhere for a day.

Why do it like this?For other reasons than stated above, the O ring and the cam gasket may not fail at the same time.Many owners are unaware of this ring when replacing the cam gasket.The 1.8 can leak oil down and ruin the heater hose..The 1.6 can leak oil down on the small unused water cap nipple.Not sure if this will hurt the cap but will guess it does not do it much good!We could pull the cam cover to do it, but will probably be spending at least 5 times longer.Even if the cam gasket is still serviceable, no need to move the coil bracket or clean the old gasket sealer from the 6 points and apply fresh sealant.

Note from Boyce Rigdon:

Ignition

CAS INSTALL GUIDE: CLICK HERE
EXPANSION HARNESSES INSTALL GUIDE: CLICK HERE

Refine Search

Cam Angle Sensor CAS TFI Distributor Conversion Kit

This kit is designed to work with Ford TFI distributors and PiMP, PiMPx, PiMPxs, PiMPxshift, Megasqu..

$279.99$299.99

CAS & Expansion Coil/Ignition Harness Kit 4 Cyl PiMPx PiMPxs

Includes both our CAS (cam angle sensor) that bolts to the stock distributor as well as the expansio..

$549.99$564.99

CAS & Expansion Coil/Ignition Harness Kit V8 PiMPx PiMPxs PiMPxshift

Includes both our CAS (cam angle sensor) that bolts to the stock distributor as well as the expansio..

$579.99$599.99

CAS + Expansion Coil/Ignition Harness Kit + IGN-1A Coils 4 Cyl PiMPx PiMPxs

Includes both our CAS (cam angle sensor) that bolts to the stock distributor as well as the expansio..

$839.99$874.99

CAS + Expansion Coil/Ignition Harness Kit + IGN-1A Coils V8 PiMPx PiMPxs PiMPxshift

Includes both our CAS (cam angle sensor) that bolts to the stock distributor as well as the expansio..

$1,149.99$1,229.99

Coil Near Plug Expansion Harness For LS Coils or IGN-1A Coils V8 PiMPx PiMPxs PiMPxshift

This expansion harness plugs into the ECU's expansion port, through the firewall, and to the engine...

$304.99$329.99

Coil Near Plug Expansion Harness For LS Coils or IGN-1A Coils 4 Cyl PiMPx PiMPxs

This expansion harness plugs into the ECU's expansion port, through the firewall, and to the engine...

Ignition Casino Scam

$274.99$289.99

Coil Near Plug Expansion Sub-Harness for IGN-1A Coils PiMPx PiMPxs PiMPxshift

This expansion sub-harness plugs into the Coil Near Plug Expansion Harness and to the IGN-1A Coils. ..

$119.99

Coil Near Plug Expansion Sub-Harness for LS Coils PiMPx PiMPxs PiMPxshift

This expansion sub-harness plugs into the Coil Near Plug Expansion Harness and to the GM coil harnes..

$64.99

IGN-1A Smart Coils (Coil On Plug/Coil Near Plug)

This High Output Ignition Coil is an inductive smart coil capable of producing extremely high spark ..

$69.99$75.99

IGN-1A Smart Coil Crimp Connector With Pins

This connector plugs into the IGN-1A coils and allows you to crimp the included pins directly to you..

$5.29

IGN-1A Smart Coil Pigtails

This pigtail harness plugs into the IGN-1A coils and allows you a head start when building your own ..

$13.99

Extra Services - Use To Order Custom Requests or Add Additional Funds

Need to pay for extra services or custom requests? You can do that right here. This add to cart opti..

$0.00

Ignition Casino Poker