ok, so I've been battling with the LT1 ignition gremlins for over a year in my conversion project. I had it running for a solid year with an accelDFI completely stock beyond headers.

I got antifreeze inside the `95 optispark but it still ran with a few misses every once and a while. It was time to change it. I swapped the engine to a new car and in the process fixed the intake oil leak, brand new optispark and taylor wires.

Once it was in the new car and ready to roll it ran like absolute ****. I started troubleshooting and ended up replacing the $18 coil, $80 ignition module, $70 IAC , $40 TPS, and a few other odds and ends. Everything was 100%, or so I thought, went through shoebox's opti test while cranking, all seemed ok. checked fuel pressure, ok. tuned and retuned accelDFI 100s of times with subtle changes with the same effect. Checked spark. Very inconsistent. I rewired my ecm leads to the coil, opti, and ignition module. didn't change anything. I checked spark again, was very inconsistent. I changed wires assuming I crimped the wires bad, checked spark looked 100% better and was consistent. Drove for 5 min then back to the same stumbling problem. Changed the coil lead wire 3 times, no change. I finally took the optispark off again (not fun while engine in the car), the ignition module off along with the coil. I got replacements for all three because they're all warranty'd from autozone. Under inspection everything looked 100%. I noticed after tearing down the optispark I forgot to assemble it with a thin tin disc that sat over the daisy wheel with the grooves the LED sensor reads off. I somewhat doubt this was the cause for my horrible ignition trouble, but after getting all the items replaced and back together 100% this time everything runs perfectly.

anyways, thanks for all the help from the board, shoebox, one2try, and those that helped me tune the accelDFI. car runs really nice now.

 

LT1 in a Jag, that's cool.