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1996 BBB
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Discussion Starter · #1 · (Edited)
I have a friends car that I am going to look at tonight, no injector pulse and no spark...

I am thinking either ICM or the opti sensor or opti harness.

One question I have is if there is a way to check the low resolution signal? I know you can check the high by spinning the opti slowly and looking for 0-5 volts as the windows pass, but it is my understanding that the high resolution signal wont cause the car to not run in most cases. If the car isn't getting injector pulse, it sounds like the PCM doesn't know the position of the engine which leads me to believe it would be a low resolution signal problem.

Any other help in diagnosing this is much appreciated, I am pretty sure the problem is narrowed down to ICM, opti sensor, opti harness or a wiring/ground issue to either of those but if anyone has any other ideas on what I can check out it would help me a lot. thanks
 

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Registered
1996 BBB
Joined
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1,710 Posts
Discussion Starter · #3 ·
Swapped his ICM with my old one, redid his grounds because they were crap, checked voltage at opti harness and got the 12v 5v and 5v. Still no injector pulse or spark, it's a new coil he told me.

Went to hook up the scanner, computer was not communicating with the scanner. It was around this time that he had to leave for work so im going to look at it later this week.

Figure the OBD2 power is on the same fuse as the cig lighter? So I'll check that and try to get communication with the scanner. I'm betting it's the opti but I want to see if I can get any stored codes off the computer first. Think it could be a PCM issue, with the opti and injectors all getting the proper voltage? Seems more likely to be the opti to me...
 
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