Optispark Troubleshooting
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Joined: Jul 2005
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From: Athens, GA
Optispark Troubleshooting
I have a friend with a '92 LT1, and I'm trying to give him some long distance support.
Here's what I know:
Here's what I told him to try:
Did I overlook anything obvious? Anything else we can recommend that he take a look at?
Thanks,
Steven
Here's what I know:
I am getting a code 16 Low Resolution Pulse not being read and I think it is the Opti. I am going to change it out this weekend. I checked the manual and the computer is sending the voltage to the pigtail (red/black wire A) properly. The car has a broken clip on the connector but it cuts off when it is just sitting there. I thought it might be hitting a bump and knocking it loose. It also cut off when I moved the tach filter that connects to the coil. Have you known anyone who has had this problem and fixed it?
The Code 16 is indeed the Low Resolution pulse. Fundamentally, the Low Resolution pulse tells the ECM which cylinder is ready for fuel injection pulsing and ignition firing.
To troubleshoot, here's the quick and dirty thing to do.
Check the wiring connections, especially the pigtail connector from the Optispark to the main wiring harness. This is the black/red wire that goes to terminal "A" on the pigtail connector. On the 1992-93 ecm, this is wire C5 (green connector). If the wiring checks out (which you've indicated it does), you will have to replace the optical sensor module in the distributor.
I'm disturbed by the broken clip, as that may have allowed just enough corrosion over time to interfere with a good signal. These signals are typically low voltage/low current, so corrosion and intermittent connections can be an issue.
To troubleshoot, here's the quick and dirty thing to do.
Check the wiring connections, especially the pigtail connector from the Optispark to the main wiring harness. This is the black/red wire that goes to terminal "A" on the pigtail connector. On the 1992-93 ecm, this is wire C5 (green connector). If the wiring checks out (which you've indicated it does), you will have to replace the optical sensor module in the distributor.
I'm disturbed by the broken clip, as that may have allowed just enough corrosion over time to interfere with a good signal. These signals are typically low voltage/low current, so corrosion and intermittent connections can be an issue.
Thanks,
Steven
