wheeljo2

I am working on a 94 LT1 convertible corvette and the previous opti-spark distributor bit the dust. I opened it up and much to my chagrin both of the rotor bolts had come out. I replaced both the water pump and the opti-spark and went to fire it up last night and it would not start just turn over.

It was weird because at one point it tried to diesel a little bit but that was it. I pulled the coil wire off the coil slightly and it had ignition there. I installed the new harness that the opti-spark came with as well. Only thing I did to the new opti-spark was lock tight the two bolts that hold the rotor down and silicone the cover back on to prevent moisture.

What is the best way to troubleshoot my situation? Also, I have a spare coil and lower module and I plugged it in without mounting to the engine (not sure if it needs to be bolted on to ground) and it did the exact same so hoping that rules out the coil or module below it.
I also made sure the wires were sequenced correctly top to bottom right to left.

Any help you can provide will be greatly appreciated.

pkincy

Let me give you some thoughts. The current batch of offshore made OptiPukes are a bit notorious for being DOA. I know you don't want to hear that, but it happens way more than it should. What source did you use to buy the new one?

Also I have heard that it is possible to force it on in an incorrect position. I have never had a problem with that, but then again most of my Opti replacing was done back in the 90's when we could still get OEM parts.

First thing I might try is replacing the coil wire. I have had one go bad and that simple replacement enabled me to not go back under the water pump.

The other problem I have had is having a simple brain fade and forgetting to reconnect everything correctly.

I likely have replaced 6-7 optis and in about 5 of the cases that was not the actual problem. Do replace the coil and ignition module. Why? You have it and it is easy to get to.

Good Luck.

Silver96ce

On my '96 they changed the drive on the back of the distributor from spline to pin. So I don't have firsthand knowledge of the gen I opti. The spline plug on the back of the unit is keyed so that it can in theory only be installed one way and correctly. But from what I have read it is possible to push the opti on with the spline (and the rotor inside in the distributor) in the wrong position. And it seems that it happens somewhat regularly. That would cause your no-start condition. I would pull the opti and double check it is correctly lined up and installed.

pkincy

You are correct, but with the OEM Optis that was very hard to do, as there was clearly only one orientation where it would slide all the way in. However these new optis may not have as clearly machined a key.

wheeljo2

Thanks Pkincy & silver96ce, I spent this evening trying different things all to no avail. I am afraid that the new opti I got was DOA. I purchased a new opti back in 2012 from OReilly with a lifetime warranty thinking this would be the better way to go since it is a weak link in the ignition system. It is a RPT unit or Richporter Technologies Ltd. of course like you said made in Taiwan. The replacement opti under warranty had a slightly different cover and also had a vent tube at the bottom but the back end hook-up was the same in that it has a small pin that is geared on both ends and there is a key slot so theoretically it can only go on one way I can checked the orientation inside the engine and matched it up exactly with the opti when installed and it slide all the way back flush before any bolts were installed.

I had a spare used delco coil and ignition module and I swapped it out and still no start. However, I am getting an ignition spark at both ends of the coil wire just like I did before the swap. Also, I pulled off one wire from a plug and stuck a spare spark plug in it and it had ignition as well however in all cases the ignition spark seemed weak to me at there was no clicking or popping just a mild ignition stream.

I also sprayed some fuel down the throttle body to see if it would hit thinking maybe the fuel pump was out but it still would not fire so I am thinking a definitely have an ignition problem. Going back to Oreilly's tomorrow demand yet another opti-spark and I plan to test it after it installed to see it the motor fires for a sec before I put the water pump and everything else back together, no faith in this part for the time being.

1993C4LT1

Honestly, I wouldn't put another opti from o reilys. I would buy a Petris. A few of us on here have an opti from saccitycorvette. Dumb question, but did you put the plug wires in the correct connections going to the opti?

antfarmer2

And did they click twice?

wheeljo2

Thanks guys got it fixed! Then first new opti I put on was bad!?!?!? But the next one worked and I bolted it on, wired it up and tested it before I put it all back together. Hard to believe a new opti that would not work where is the QC these days, I guess they don't believe in that over in Taiwan. Thanks for everyone's help and I ended up changing the plugs and wires while I had it down.

antfarmer2

Good job!!!!!!

Silver96ce

Good to hear.

1993C4LT1

Now time to enjoy
Plus, the weather is great here in DFW