Mitsubishi Repair: 91 mitsubishi montaro suv 3 litre automatic, camshaft sensor, mitsubishi montaro

Question
In my second letter from you I decided I was going to try what you said, but before I did anything I was going to try to start it one more time. To my surprise it started right off and did not konk out when I accelerated the pedal. I was half scared to take it for a ride for fear that once I shut it off I would not be able to start it again. I took it for a ride and shut it off, it restarted right away.. I did this three more times and it started right up. I had it parked in front of my house and was going to put it in the garage, and lo and behold it would not start again. I checked all the wiring and everything seemed tight, I even checked to see if it was getting enough fuel and it shot gasoline about four feet so I assumed it was getting enough fuel. I was wondering about something on my distributor called a photo-optic sensing unit. Exactly, what is this and what does it do. I ask a fellow at church and he said this tells you when you should get fuel to a certain cylinder. If he is right could it be that it works perfect one minute and not work the next. When the engine does run, it runs perfect with no misses or any other problems. I hate to be such a pain in the butt but it is driving me nuts. The nearest dealer is over 200 miles from where I live and I really don't feel like paying such a high fee that they want, that is if I could even get it started to get there so I am relying on your expert opinion.

Thank you,

Harry Snyder


Answer
Harry,
I've only heard of a photo-optic sensing unit on a camshaft sensor.  That sensor uses light to to tell the ECU exactly where the camshaft is and which valves are compressed (open).  It' a critical component in keeping the correct timing.

But there still could be a problem with your distributor and/or related components.  The rotor on the distributor cap may not be spinning fast enough or could be getting stuck.  Also, your points could be worn down.  Any local mechanic can check these items.  You don't need to take your car to the dealership for this issue.  
Good luck!