1G Cam position sensor

[bomper04]

I believe my cps is defective/not working. is there a way to test it without bringing it to the shop...? and what are the symptoms of a broken cps..

 

[kenamond]

What are the symptoms that lead you to suspect the CPS?

I'm still confused by the fact that 95s have a CAS and CPS but they moved the CAS after that, and I'm not sure if the post-95s have a CPS. I'd have to re-read the Haynes manual and peek at my manualcd to clear this up in my head. My CAS started flaking out, but it started working after I wiggled the CAS wire (I didn't know this was what caused it to start working at the time). After it started working again, it then decided to throw the code.

But my symptoms when the CAS was "off" were startup, rev to 2500rpm, drop to 500rpm, idle like crap, black puffs of fuel-ladened exhaust, stall. I could sometimes keep the car running via the throttle for a few seconds, but it'd stall anyway.

Because it threw a CAS code, I finally figured out the '95 vs. post-95 issue, replaced the CAS, and fixed my problem, so I never had to figure out if a post-95 even had a CPS.

If it is the CAS, it costs a bit (I think $80+ for mine at Autozone), but it takes literally a minute to swap out on post-95 cars (it's tucked under the intake cam gear/sprocket on '95s and a PITA to change compared to the later models).

Anyway, posting your symptoms might give others (with more knowledge than I) more of a hint.

 

[kenamond]

Simple test ----
Unbolt the CAS from the car.
Turn the key to ON (dont start the car)
Spin the CAS and make sure you hear the clicking of the injectors

Detailed test ----
- Disconnect CAS connector.
- Measure the voltage on harness side CAS pin 3 (red wire) with key on - should be +12V.
- Then make sure you have continuity (0 ohms) on harness side CAS pin 1 (black) to ground.
- Then measure the voltage on harness side CAS pin 2 (blue/red) with key on - should be 4.8-5.2V.
- Reconnect CAS connector.
- Measure voltage on CAS pin 2 (blue/red) while cranking engine - should be 0.4-3.0V [engine idling should be 0.5-2.0]. If you have 0V your CAS is dead since you should read something (even though they are pulses the voltmeter will read the average which will be more than 0). Note: To get at the wire inside you can stick a safety pin through the insulation and connect voltmeter lead to it.

Yer faster than I. How do you spin the CAS? It's all encased in plastic, right? And if you don't mind...do the post-95s have a CPS?

 

[absolute_DSM]

Yer faster than I. How do you spin the CAS? It's all encased in plastic, right? And if you don't mind...do the post-95s have a CPS?

Ah crap Im so used to 6 bolts! That post above should be disregarded.

Yes the 95-99s have the "CPS" and the 90-94s have the "CAS". At least, thats the way Mitsubishi sees it.

95-99 CPS Testing
With engine cranking, voltage between the #2 terminal and ground should be 0.4-3.0 volts. (0.5-2.0 volts while idling)

Disconnect the connector
1 - With engine cranking, voltage between the #2 terminal and ground should be 0.4-3.0 volts. (4.8-5.2 volts while idling)
2 - Check for continuity between terminal #1 and ground, there should be.

If everything checks out, replace the CPS, if not you may have a wiring problem or a faulty ECU.

A faulty CPS would probably not let the car run at all and it should throw a CEL.