I have an issue that caused me to sideline the 92 vette last Monday. While on the way to work (only 2 miles from home) I noticed that the car was not accelerating when I tried to gain speed moving up a hill. I pushed the clutch in and my suspicions that the motor had died was confirmed. Letting out on the clutch to pop start the car led to a series of backfires that I think was due to unburnt fuel entering the exhaust manifold. When the car came to a stop off the road, I turned the key to attempt to start the car, and the car started like nothing was wrong. I managed to limp the car back home. I noticed that the car seemed to be lacking in power.

I assumed that it was a bad opti as I have had failing optis do the same thing as what just happened. I ordered an opti from a guy on Ebay who claimed that the unit had Mitsubishi sensors in the unit and that he had a stock of them. Furthermore, the guy who sold me the opti sent me a video of the opti working on an oscilloscope that show a good high and low-res pulse. When replacing the opti I decided I would go ahead and remove the intake to fix an oil leak that was coming from the rear of the intake. After everything was put back together I tried to start the car with no luck.

I have a LTCC set-up; and I have 12V to the box; also made sure that everything was hooked up and that it was right. I have gotten two different codes from the LTCC module; one of them being a cylinder decode sequence failure, and the other being no EST signal. (No codes from the ECM by the way) Every fuse has been checked. The fuel pump runs, and the O2 sensors and the knock sensors are new (but those won’t prevent the car from running until the car switches to open loop correct?) I have oil pressure. The only thing I have found that is clear, is I have no spark. I’m wondering if the LTCC box died on me. Also, I have noticed that when I try to crank the car it sounds like the compression stroke blows through the intake. I haven’t ever noticed that, but I haven’t had the car not start but a few times. Attached is a video showing me trying to crank the car. Any help would be greatly appreciated.

The forum would not let me upload the video because due to some security certificate issue, so I posted the video on youtube... Here is the link: Thanks,
Connor

 

Turned out to be another opti failure. Dead on arrival. Now i have a spare LTCC unit!!

 

At least you got it fixed.Did the guy you bought the opti on ebay replace the first?
And since i recently aquired a 92 as well but haven't read everything in the shop manuals what is the LTCC? it's a new one for me.

 

I'm in the process of getting a refund. Hopefully everything goes well. LTCC is a conversion from 1 coil to a coil near plug set up. It takes the high voltage out of the optispark, so its only function is to act as a sensor.

Here is a link to the page I made about my conversion https://www.corvetteforum.com/forums...e-install.html

Connor

 

Ok Connor,i'm sure you will get your refund and thanks for the link.
I'll check it out.