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  • #16
    here is a proceedure to troubleshoot the ignition system........

    Step 1. Connect a spark plug tester to a spark plug wire and
    check for spark while an assistant is cranking the engine.
    Check each plug independantly. this checks for open
    spark plug wires. Spark in one or more than one wire
    indicates the problem is in spark plug wires or optispark.
    If no spark exists, go to step 2.

    Step 2. Check for spark at the coil wire with the spark tester
    while cranking the engine. A spark indicates the problem
    is in the distributer (optispark). If no spark go to step 3.

    Step3. Perform check on ignition coil.
    a: Unplug coil electrical connector and check pink wire for
    12v. If power go to b.
    b. using ohmeter low scale, hook up the leads to the
    primary terminals on the ignition coil. Should indicate
    very low resistance. If not, replace coil.
    c. Using the high scale, hook up one lead to the primary
    terminal, the other to the secondary terminal. Should
    not read infinite resistance. If it does, replace coil.

    Step 4. Disconnect the ignition module connector and with the
    key on, check voltage at terminals A and D on the harness
    side of the connector. (pink/black and white/black wires)
    If under 10 volts check for faulty circuit from the ignition
    module to the coil or check for grounded external coil
    circuit. If 10 volts or more, change the voltmeter to a/c
    scale and measure voltage on terminal B while engine is
    cranking. (white wire). If 0 volts, Have ECM checked. If 1-
    4 volts, with the key off, disconnect the module
    connector. Install a LED type test light on the positive
    battery terminal and probe terminal C on the harness side
    of the connector (black wire). The light should illuminate.
    If not, check ground wire in the harness to the module. If
    the test light is on, go to step 5.

    Step 5. Remove the coil wire from the coil and ground it to the
    frame. Connect LED test light into the optispark harness
    connector red wire terminal C. The harness connector that
    you will use is located on the passenger side of the
    engine up near the fuel rail. You will need to insert a back
    probe pin into terminal C. If the test light flashes when an
    assistant cranks the engine, the optispark is suspect. If
    no flashes, replace the ignition module.

    If the above tests results are correct and there is still no
    start, it is tough to to tell the difference between a
    faulty module or optispark. Module = Cheap$$, optispark
    =moderate $$$.

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    • #17
      next

      ok im going to try to probe the optispark connector near the fuel rail. im goint o geta pin an probe terminal c like it said with the led light however can i use any led light i have laying around? next- when i took the coil to autozone they tested it said it looked bad but he wasnt sure. we were getting low resitance in the primary winding which is normal and high in the secondary but the nipple for the wire was corroted. he hooked a meter up to the module an we did get some resistance through it but he wasnt sure an im not quite sure either. any suggestions. if its not the ignition module then imma just take it someplace an have them mess with it im too aggravated with no tools meters or stands. thanks -chris

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      • #18
        optispark price

        optispark from dealership ac delco is $698.00. autozone has a cap and rotor "kit" from wells for $171.99 now cap and rotor kit is that the whole assembly? also, i was reading in the haynes manual, not only must the optispark unit itself be replaced but everything else including all harnesses an connectors- i think thats b.s but what do u guys think?

        -chris

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        • #19
          ok

          ok buddy of mine has a friend who is a mechanic an hes gonna let us borrow his shop an tools. im gonna replace the optispark with the autozone wells replacement any suggestions?

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          • #20
            You can usually test a suspected heat related failure in an electrical circuit by using a hair dryer or heat gun (set on low) and a can of refrigerant spray to chill it back down - you can try this on the spark control module if you suspect it. At work, we actually boil coils in a tank of water while they are making sparks to try to get them to fail. I would also look at connectors to the MSD because they are trouble points as well as the MSD itself. I would bypass the MSD if you still have a colil that the stock ignition can fire. Anyway, I would do this stuff before the opti cause it is easier and cheaper, although 94s do have a problem with optis and it may well turn out to be the problem.

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            • #21
              i replaced module

              i replaced the igntion module today an it ran great for 2 hours of driving! i thought it was fixed! however out of nowhere the car stalled an didnt turn over but cranked fine. we rolled into a parking lot and let it sit for about 2 hour while we waited for a tow truck. after only 2 hours it turned over for about 30 seconds but then died. i mean if the optispark (distributor was gone wouldnt the car NOT fire up at all?) however i might try to bypass the msd box. what does that ignition boost control box do anyway? im prety sure it just reacilberates the pcm if you decide to retard the boost right? i mean teh supercharger wouldnt spin past its preset limit of 6psi right? lastly im not sure where in the circuit the msd box is.. is it after of before the pcm? also where is the diagnostic connector located on these cars... under the dash? i read if i jump pins 5 an 6 i can jump the car in a diagnostic mode. thanks

              -chris

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              • #22
                oh optispark

                oh the optispark dist was also replaced about 2 years ago (40k) ago the origional owner said so im not sure.

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                • #23
                  The MSD turns the stock Kettering type inductive ignition to a CDI and it can pull timing out from the BTM or other gadgets hooked up to it. You should be able to bypass it and run the car without it. All the MSD stuff is after the PCM commands a given spark advance, so it will not show up in the computer.

                  You have replaced the coil & module - the MSD box is the next most likely suspect.

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                  • #24
                    I would do as Kevin suggests and bypass the MSD. Something is getting heat soaked and going south.

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