Ok, this LT1 isn't in a thirdgen, its in my 97 Camaro SS, but the 4th gen oriented sites have been no help at all, so I'm hoping someone here may have some ideas.
The engine in question has about 3000 miles on it, and is stock except for headers. It replaced the original (37,000 mile) engine, which had a catastrophic connecting rod failure, and was swapped in a few months ago. The car had been in storage in a damp area for a couple years, and I had to replace the Opti recently as a result. Its a new GM Opti, and it ran fine with it for about a week.
Here's the problem; the car had been running and starting fine, but now it won't start. The car will turn over fine, and the fuel pump is coming on, but there is no spark at the plugs (checked two). I also checked for fire at the coil wire (none), and replaced the coil and module. No change. All the fuses for the PCM, injectors, etc are good. There are no obvious problems with the wiring. I have tried two different keys, thinking it might be passkey/vats related, but no luck. The car was coding (likely for the rear O2 and AIR pump, since the cats are gutted (by a speedbump) and the air pump hasn't been reinstalled.), but I didn't check the codes then and for some reason my scanner (its a cheap one, basically just a code reader) isn't showing any codes. Does anyone have any ideas? As bad as I hate to, I'm going to tow it to the dealership if I can't figure out something soon.

 

Are you sure it was the correct opti? I've heard of incorrect opti's running for a while and having the wrong size dowel pin tearing up the opti.
I dunno. If you take it to some place and get the code read, I could look it up for ya on GM Service Information, and see what it's for.
Also check the grounds in the ignition system. Maybe there's a problem there. It's hard to tell, but def. sounds like an ignition problem.

 

The opti is correct, and I even pulled it back off to make sure there was no problem with the alignment of the dowel pin. Everything looks fine. I really don't think its the Opti, since the coil isn't sending spark to it. I haven't noticed any bad /loose grounds, but I'm still checking. Thanks for the offer on the codes, but I do have the factory manual and all that is listed; for some reason the scanner just doesn't show any. Weird.

 

a have heard a lot of guys on the camaroz28.com board say their opti's lasted a few weeks and took a crap again.

makes you feel good about the whole setup in general doesn't it.

 

I'm thinking about putting the old one back on to see if the car will run...though I'm not sure if a problem with the Opti would circumvent the ignition system getting spark to begin with. As screwed up as the electricals on a late model car are, its a good possibility. If I keep the car (been thinking about selling it to buy a late third gen convertible), I'll probably get that Opti replacement system they advertise on camaroz28.com (its in this months GMHTP also).
One thing about having owned three LT1 F-bodies; I'
m getting really fast at changing Optis! I did the last one in less than two hours, and wasn't in a particular hurry.

 

I had a similar problem with my LT1, wouldn't fire spark plugs or fuel injectors, but mine gave out a code 16? Optical sensor or something like that.

Basiclly the opti wasn't gettting a good reading for spark timing from the optical sensor. If it doesn't get a good signal from this it won't make a spark or fire the injectors.

 

I'm betting you are right Drastius. I have checked everything else that I possibly can, and keep coming up with nothing. I may swap on the old opti tonight to see if it will start. Good thing GM parts have a warranty at least.