Is there a way to diagnose the optispark optical sensor to determine if it is malfunctioning. This is with the optispark apart.

I am familiar with diagnosing the signals coming into the optispark and in my case they all check out ground/5v/5v/12v.

Just trying to diagnose my problem of no start.

 

If there were problems with the feedback signals of the opti, there would be DTC's set. One lights the SES, the other does not.

You could look at the signals with a meter but would have to move the rotor very slowly to see the change from 0 to 5 volts and back on the high res side. The low res side is easier to see since there are only 4 signals per revolution.

You should start with the basics. check for spark on at least 4 cylinders 2 up front and 2 in the back. If that pans out try squirting fuel directly in the intake while someone cranks it over.

 

Sure you get a code for low or hi res out of limit or what ever it says. Some cars also get a CPS code.

 

What are you referring to as a CPS? do you mean the CKP or crank position sensor?

Well the 95 that this person has does NOT have a CKP. And if he did, a CKP code would not have any effect on the engine since a CKP is only used to monitor misfires.

 

Are you sure that even if you don't fire, you get a DTC? I have Scanmaster and had it hooked up just to confirm such an issue.

could there be other issues that don't come up as DTC's with the optical sensor?

Ben

 

The only codes related to the Opti are for the high and low res pulse patterns from the optical sensor. There are no direct codes set by problems with the high voltage (cap/rotor) functions.

What problem are you trying to fix? Did this not set DTC 16 or 36 with the Opti in the car? Since you have already pulled the Opti out, all you can do is follow Speedy's suggestion, power it up, rotate the wheel and verify that the light passing through the slots in the optical wheel is causing the voltage to vary in a squrae wave between 0V and 5V. If you could put it on a scope, you could also verify the square wave.

 

I've never looked at any data sheets for it, but if its like any other optical encoder, then you just give one pin voltage, one pin ground, and another pin will either be a varying 0-5v output if its analog, or a square wave with a duty cycle between 0-100%.

 

i might have same problem...WOW I'm stumped just trying to understand this. Since mines still in the car as its meant to be, How can i check it?

 

You are right I was not even thinking. I should have looked for it being a 95 and Yes I meant CKP. As for the p0336 on a 96-97 car the constant SES for it is a first sign of a Opti failure.

 

Injuneer,

No codes through Scanmaster with this opti. I replaced the opti because I was getting both of those codes.

I am trying to find out why my car is not firing after opti replacement. What is guaranteed to be good:

fuel, ICM, All PCM signals to ICM, coil, wire from coil to opti, signals from PCM to opti, all fuses, PCM, cam is rotating therefore chain not broken.

What is left to check: actual firing from coil to opti, carb cleaner in TB to confirm injectors are working.

I had an extra optical encoder from an old opti that was working when I pulled it a year ago and have used that.

 

Did you check for spark at any plugs? Much less 4 like I suggested?

 

Yes on one plug: #1 and I have spark.

I will try and figure out how to rotate that opti...