Resolved green top CAS vs black top CAS

[spitefire1]

Hey i have a green top CAS on my 91 now and i've heard that a black top CAS is a better CAS sensor. Is it worth buying and putting on my car? Like is there any wiring i have to do or does it bolt right in? Will i see a difference in performance too?

Someone please help thanks

 

[Rob10_99]

If you had a choice to buy one or the other, it really doesn't matter. The plugs are different so you will have to pull the pins out of the connector on your old cas for plug and play.
The blacktop is the light type and the rest are hallman type(anyone have infos on this post it)

 

[blackGSX2g]

If you had a choice to buy one or the other, it really doesn't matter. The plugs are different so you will have to pull the pins out of the connector on your old cas for plug and play.
The blacktop is the light type and the rest are hallman type(anyone have infos on this post it)

The plugs should be the same, the only difference was with the 89-90 style sensor.

The 89-92 sensors use an optical sensor and a slotted rotating disc. The 93-94 black plastic cover sensors use a hall effect sensor with curved metal plates.

It's been said that the hall effect will have a lesser chance of the random misfire code in a 6-bolt swapped 2g since it utilizes the same type (hall effect) of sensor as the 2g cars. That said, before I got DSMLink I still had the RM issue with the black top CAS on my 2g.

Also, I've heard the green top CAS is less prone to electrical interference from aftermarket ignition systems.

 

[srumel]

Actually, the black tops are the Hall-Effect type sensor. These are supposed to have a higher resolution signal than the green tops. If your green top isn't broken, don't buy a black top. You won't notice a difference in performance.

 

[8urwrx]

The plugs are the same. I swapped my green top out with the black top with no problems after my green somehow took a dump on me.

 

[ramsack]

I don't get how a magnetic signal would be better than an optical one, but that's just me. Can the 91-94 ECUs read the 90 (optical) CAS signal?

 

[Ceddy]

I don't get how a magnetic signal would be better than an optical one, but that's just me. Can the 91-94 ECUs read the 90 (optical) CAS signal?

Hall Effect sensors respond faster and have a better signal quality, where Optical sensors are kind of sluggish. Almost everyone (Manufacturers) have switched to Hall Effect sensors now for Crank and CAM sensors, Optical sensors are kind of outdated.

You can use either type sensor with your ECU, 99% of the time you won't notice any difference.

 

[LiquidX]

+1

If you need one, just get which ever is cheaper. Both do the same thing without issues. The blacktop is supposed to have a better signal but it's nothing to frett over.

 

[AWD92TalonTSi]

I'm running a bolt in my 2g and have a green top sensor. I've had the random misfire code for a while and paid no attention to it. I went to check/set base timing and when I put the timing light on wire #1 it was not a consistent flashing. Every other second or so I could see it not fire then fire again. I checked the rest of the wires in this manner.

I had new plugs sitting around so I tried replacing those. I also measured the resistance of the primary and secondary coils, then I went to the store picked up some plug wires and still no change.

The only thing left is the cam sensor, is there a chance the blacktop would be a better pick for when I get a new one?

Thanks,
Bryan

 

[snowborder714]

A blacktop is usually a better choice for a 6 bolt swap as it has higher resolution than the green top, but it's not guaranteed to get rid of the random misfire code.

There's 2 ways to get rid of it. The pot mod (search 1gina2g on Google and click on the first link, which is a PDF). One of the last pages in that will explain it. The other is ECMlink, which just requires a check box to be marked to keep the ECU from looking for certain check engine lights.

And when checking base timing, you have to ground it. The only way to do this on a 2gb is to use ECMlink.

 

[AWD92TalonTSi]

I was going to do the potentiometer mod but it seems as though I have an actual misfire. Also I used evoscan to "ground" out the timing adjustment.

Bryan

 

[snowborder714]

Have you checked to see if the CAS is 180* out?
RRE Instructions

 

[AWD92TalonTSi]

Have you checked to see if the CAS is 180* out?
RRE Instructions

I'm pretty sure I got that. The car drives good and pulls hard. Pretty sure it wouldn't run for the most part if the CAS was out 180.

 

[snowborder714]

It might run, as I've tested it out on mine. Not saying every car will be the same, but there wasn't a huge difference with mine when I tested both ways.

Does this happen all of the time, or just after a short while of driving? Before I got DSMlink, I had a random misfire issue where after a bit of driving, my car would go into limp mode. Wouldn't boost, would really struggle to go, sounded horrible, etc.

 

[AWD92TalonTSi]

It might run, as I've tested it out on mine. Not saying every car will be the same, but there wasn't a huge difference with mine when I tested both ways.

Does this happen all of the time, or just after a short while of driving? Before I got DSMlink, I had a random misfire issue where after a bit of driving, my car would go into limp mode. Wouldn't boost, would really struggle to go, sounded horrible, etc.

It's always idled kinda rough. Driveability is fine. On a few occasions it has gone into limp mode, resetting the computer fixed it.

It's just this weekend that I had a timing light on it and noticed that something isn't firing 100%. I'll check the CAS then.

bryan

 

[Ceddy]

The only way to do this on a 2gb is to use ECMlink.

There are other options, but if you have a 97 ECU you are screwed either way.

Misfire Code
95 -> ECMLink, or DSMChip with Misfire Removed
96 - 97 -> Pot Mod
98 - 99 -> Turn off Misfire Code with OpenPort 2.0 cable

Base Timing
95 early -> Ground Terminal
95 late - 96 -> Need to add wire to ECU harness, and ground it.
97 -> Snap-On Tool or EvoScan, to set base timing (Haven't tested personally)
98-99 -> Flash with CeddyMods, or Snap-On Tool or EvoScan

The Pot Mod does work, but was created when there were no other options, there other options out there now.

 

[snowborder714]

Thanks for the additional info! Didn't know about those options.