Im not getting any spark now so i did a few tests.
1-unplugged the coil wire and checked for spark...nothing
2-checked voltage on the pnk/blk-11.54V and wht/blk-10.21V at the ICM
3-checked AC voltage on on the wht wire with engine turning over...nothing
4-checked continuity on the four wires on the opti to the PCM...checks
out fine.

now for the question.
1. im not sure im using my meter right to check the AC voltage.
i switched the meter to V~ 200 and left both of the wires in the same plugs. am i correct?

I still have to check the continuity of the white wire to the PCM but assuming that it checks out, how do i tell if its my PCM or my opti causing the problem?

also my SES light is not blinking at all when i plug my code reader in, but it does come on when the ignition is switched on. any ideas on this? i checked the wires at the ALDL connector and they look fine.

 

checking for AC voltage when cranking the engine over? As in you are looking for an engine rpm/timing signal? that should be extremely low AC voltage. like less than a volt if you are comming from a cranksensor. then again its stupid optispark so who knows what itl be

 

well,.. i know i should have between 1-4 volts AC but im getting nothing. just not sure if ive got my multimeter on the right setting.

 

What he's looking for is the Ignition Control signal from the PCM to the ICM. It will be (as he said) 1 to 4 volts AC.

I think your setting of 200 volts is too high. go to a lower setting first.

Additionally you have a rather large voltage drop at the coil that is not good. You need to track down where it's dropping assuming your battery voltage is at a normal 12.6 V.

Measure the voltage across the battery with the key off and then on. Then compare those readings to the ones at the ICM. The voltage to the coil comes from a fuse under hood, start there with the fuse out and see that the voltage doesn't drop.

Then it's time to confirm the feedback signals are coming from the opti. Put the voltmeter on DC and measure from the pink/black(ground) wire to the red/black(low res signal) wire. Now rotate the engine by hand and see if the signal changes from near 0 volts to near 5 volts and back again near 0 with the key on. The best place to pick up the signals is at the PCM but I don't know the pin outs of a 93. If you do it there, you will prove the wiring is good as well.

 

well from the problem your describing and the problem I had with my 93' ta. I would say it's the icm. I was also getting volts to the icm, around the same as yours, it won't neccesarily be 12.6 volts. esp. if you were cranking on it. how old is the icm, if it's original I would bet on that. mine fired right up after new icm. the chances of your icm failing is alot better then the computer acting up.

 

hmm... thats as low as my multimeter will go on the AC scale, i only have a 700 and 200 setting.

this is probably from my battery being somewhat drained and my electric water pump is wired to run with the key on causing some power loss.

i'll get to the tests speedygonzales described as soon as i get a chance.

thanks.