I have a 97 Z with a crank but no start issue. I have looked over the forums and found nothing like I have. Has run like a Swiss watch until now. 97k miles. Was going for a little cruise last weekend and just as I pulled into the driveway, it died. Got it to fire up but the second I stepped on the gas it died again. It fired up a 3rd time and I got it into the garage, and then died. Wouldn’t start after that. Cranks just fine. Dug into it this weekend and have no codes. Checked spark, good. Checked injector pulse, good. Checked fuel pressure and the second I rolled it over to check pressure, it started and ran. At idle with pressure regulator unplugged, 44 psi. Ran great right until I stepped on the accelerator, it shuddered and died. I can crank and get nothing but as soon as I stop cranking, it will fire 5 or 6 times BACKWARDS???? Replaced the temp sensor, Map sensor, and fuel filter this spring when I got it out of storage. Temp gauge did not work, ran like crap and had map sensor code, and was doing 100k maintenance on it and figured it could use fuel filter. Put 200 miles on it since then and now dead in the water without a paddle. Any help greatly appreciated!!!

 

Sounds like what I've experienced with the ICM failure. Mine used to fail about every two years. I finally got one from AutoZone with a lifetime warranty and every two years I'd end up swapping it out but only had to pay for the first one. Now I've changed over to the Torqhead 24x ignition and so long ICM and Optispark!

 

Try scanning it for codes.

Original Opti?

Engine modified in any way?