I have spark coming out of the coil on my 1994 LT1. I have erratic spark coming out of the opti. brand new opti. tested out the wires very low resistance. not sure what else it could be.

 

this is my third opti. it is a spline based Opti and have a good healthy spark coming out of the coil. trying to get this car shipped back home before i leave island from the military. Any ideas are welcome.

 

What brand Opti? Did you loc-tite the rotor screws before you installed it?

 

If the coil shows good spark but the opti does not. It could only be due to a mechanical problem.

Wires not making contact at either end. Could be a problem with conductivity through the cap and rotor. Problem with the rotor not making sufficient contact with the cap. Not likely broken traces within the cap itself but easy enough to check with an ohm meter.

Or miss timed opti install. Where the rotor is in between contacts when the coil fires.

If that is the case, you can check it by viewing where the rotor is in relationship to a particular cylinder being at TDC. ie, rotor should be in the near 7 O'clock position when cylinder number one is at TDC. Kinda between 6 and 7 O'clock.

 

yes i locktite the screws on the rotor when i put it in. and i have checked all the wires and i still have nothing. the wires going into the opti show these voltages. A 5V B 5V C 12V and D is ground.

Just redid the timing on the Opti. Put the motor TDC and still got the same results.

 

First of all. If the coil HAS spark but the distributor does not have spark coming out. It has nothing to do with the low voltage feedback side of the opti. As I mentioned before.

Second, timing need only be checked, not "redid". Only if it was miss installed would it have had to be redone. In checking it, it would depend on what cylinder is at TDC and what position the rotor was in.

I'm still not convinced you have it installed correctly.

Assuming it is.
The logical step at this point is go back and start over with regards to spark actually coming from the coil on a "repeatable" basis. Using a plug wire in the coil and a spark plug connected to the wire and grounded to the block.

Now take that same wire and move it to one of the 8 cylinder positions of the distributor and again with the plug grounded to the block, check that single position on the distributor for spark. Of course, a coil wire would have to be in the coil and the distributor to do so.

Move on to the remaining 7 positions of the distributor with the same "known" working plug and wire to check each for spark.

Any of the positions that did NOT spark when you checked should be ohmed from the plug wire contact of the distributor cap to the contact inside the cap that touches the rotor. Understand?

Oh and I noticed you didn't answer the question regarding what brand opti you got??????