Help, Bad Opti or Ignition?

[RyanB58]

The car has 106k on the clock. As far as i know the previous owner never replaced the Opti. Recently, when the car is cold it seems like it is missing, however when it warms up the car ran better. Last week, if I tried to give the car a little hell she would seem like she were missing. Saturday I went to star it up in the morning(about 40 degrees out) and it would just crank and never turn over. Like it is not getting spark. Sunday it was warmer out and the car started right up. This morning I get to leave for work and it would not start again. It was about 40 degrees again and the thing would just crank. My first guess is that it is Opti, but once those go out they are toast, so because it started Sunday I am believing it is ignition.
Any opinions would be appreciated.
Thanks,
Ryan

[Injuneer]

Opti problems can be intermittent. It isn't unusual to have startup problems with the optical sensor failing to provide the correct pulse patterns to the PCM. Failure of the PCM to "find" the low resolution pulse results in a no-start situation, since the PCM needs the low res pulse to fire the injectors correctly. The bright side of an optical sensor problem is that it does set a code in the PCM, and that code stays stored for future retrieval. Get it scanned.

Hard starts can also be the sign of moisture in the ignition system at virtually any point. As the weather warms up, a cold engine condenses the humidity and sparks start finding their way to the wrong place. A moisture buildup in the Opti would certainly explain that, but so would a lot of moisture on the IC Module, coil, coil wire, plug wires, etc. Again, a scan may show evidence of problems around the ICM. But unfortunately, there are no diagnostics for the high voltage section (cap/rotor) of the Opti.

Check the ignition system for corrosion, including:
-opti high voltage terminals
-end of plug and coil wires
-opti harness connectors (1 on the body of the opti, the other a gray connector on a bracket on the passenger side of the intake manifold).

Open the hood at night and look for arcing in the high voltage wires. You could even mist **a little** water on them to see if that makes the arcing show up.

The Opti can be a problem, but there are several other possible causes that need to be elimated before jumping to the conclusion that its the opti. A "scan" might make the analysis easier.


The fact that it seems to be a problems that only occurs on cold starts, and the problem goes away when the engine warms up is a key. A faulty coolant temp sensor would make cold stats a problem.