I have a 1994 Firebird Formula 6sp LT1 with 66k. My car would run rough then after about 5-10 minutes of driving would die and not start again for a day or so.
I thought it would be the optispark so I bought a Delphi Optispark to replace the stock one.
After installing the distributor I put the motor back together except I didn't bolt the water pump down, i just plugged in the sensor. I wanted to see if it would start before I put the pump back on.

Now the motor just cranks over and does not start.
All the wires and connectors look like they're hooked up right. Is there anything else I could have messed up when I put it back together?

I tried putting the OEM distributor back on and it still won't start.

I tried replacing the coil, ignition module, spark plugs, and tested the plug wires, but it still won't start. I can hear the fuel pump and injectors working...

Could it be the PCM, or opti harness? I tried looking at gripenfelter's sticky for diagnosing an opti, but I'm not sure if I did it right.

If some could help me out I'd really appreciate it, I've been working on this car for about 3 weeks and I'm almost at my wits end.

 

its sounds like it could be a fuel problem. have you tested the injectors with a noid light? it could also be the opit plug or that you have the opti sitting 180' off.

 

I haven't tested the injectors, but a few months ago it had new injectors and a fuel pump installed.
Can the 94 opti be 180 degrees off? I thought they were splined to only go in one way.
I matched the spline position to the old distributor before putting it back in, and it went right on.

The opti connector Looks kinda like it melted a little or something but all the metal connectors seem to be fine...

 

yes they are splined. not that i think about it no they cant be 180 off. were the injectors used or new when they were put in?

 

I've heard of Opti's being installed wrong, i know on my 97, there are 3 channels in the back of the dist., one is "notched", the others aren't, the one channel with the notch goes over the cam key, don't know if the other channels will go over the cam key, but this could be the issue, just doesn't make sence it would start brfore (maybe not run good) but won't start now.

 

The injectors were new. The 93-94 optisparks are splined with a key to only go in one way, if the key is off the distributor won't sit flush at all. 95-97 have 3 channels and can be installed 3 ways.

How can I test the opti harness?
Is there anything else I could've overlooked?

 

Check to see spark is leaving the coil. Pull the coil wire out of the opti aim at the block or tb then have someone crank it over. If you see spark the coil/icm is good. Then reconnect the coil wire to the opti and take out the number one plug with the plug wire on you will need to ground the plug on the block then have someone turn it over. If the plug is sparking you are gitting spark and your problem is not the ignition.

 

Did you try scanning it? That will tell you if the signals from the Opti optical sensor are getting to the PCM.

I'd estimate as many as 10% of the Opti problems come from incorrect indexing of the splined shaft. It can and has been done..... repeatedly...... by people who swore they aligned the notched spline correctly.

Did you check the rotor on the new Opti to insure it was securely fastened? They have been known to fall off brand new GM Optis.

I'd be suspicious of a harness connector that looked "burned".

 

Did you hook up your MAF, IAT and intake plumbing? Some cars don't like to start without them. If you got things right, it might even be flooded now from all the cranking, which will make it hard to start.
You can unmount the opti from the engine and leave the electrical harness connected, then spin the opti drive and listen for the injectors pulsing (key ON). That will tell you if signals are getting to the PCM. You should also get spark doing this.