I have a 1996 Camaro Z28 5.7L LT1, 6 speed manual, with 181,000 miles. I bought it about a month ago. During neighborhood road construction, I had to drive on grooved pavement. Shortly afterwards my car developed a misfire code and ran poorly for a couple miles. It seemed to clear the problem and was driving better than ever a mile later. Friend's ZR11 read it as a "miscellaneous misfire" code was cleared and didn't comeback. Later that day, I had to go out again, again on grooved pavement. This time it died within 2 blocks of the house and has not started since.
It will crank and crank, OBD live data works and shows 180 rpm while cranking but no code, except for a MAF code from us disconnecting it while trying to find the problem. After buying it and before the issue we changed the oil to high mileage synthetic with a new filter, I also only run Costco and Mobil gas as it's top tier certified. After the problem we changed the spark plugs, plug wires, and the icm. We also tested the coil. I knew it needed new plugs and wires already, but that wasn't the cause of this problem. With starter fluid/spray fuel it trys to start, and occasionally backfires out the throttle body. Verified it has fuel pressure, fuel pump works and the pressure doesn't immediately drop after turning the key off also tested plugs have spark. I also tested to make sure the engine is properly grounded to make sure the ground strap hasn't failed. Somebody said optispark, but from my understanding if the optispark wasn't sending timing data a GM specific code would trigger and if the distributor portion was bad the plugs would have no spark. I'm at a loss and any advice would be appreciated before I tow it to a shop with proper tools.
Thank you in advance
Check the Optispark.
Most likely the rough roads caused the water pump to drip, and ANY amount of moisture will cause problems.
The Optispark system is a real headache.
Sounds like a loose connection somewhere. Corrosion in a wiring harness maybe, could be anywhere. Hooking upma scan tool so you can see live data should help you narrow it down. You could start checking plugs looking for loose connections, dark connector pins or ones that are turning green and clean em.
Thank you, while trying to crank it and with the key in the on position, we did have a Zurich ZR11 hooked up and viewing live data. Nothing stood out as abnormal, both fuel sys reported OL, but other than fuel system, rpm, air flow, and a couple other things, live data was scarse. Because it's a 96, I'm not sure if more data would be available on a more premium scan tool.
We have looked at all of the plugs and harnesses in the ignition system, but have not opened the optispark to check if water got to it or if there is corrosion in the cap. I am under the assumption it's fine as I have spark at the plugs and no code. The battery and alternator wires are in good shape as well. No green, hard to say for dark as it's not very clean and it has a couple minor oil leaks. I do live in Florida and the previous owner was near a beach so this would make a lot of since. I will break out my multimeter and see if I can find anything before I tow it to a shop. I did notice somebody had changed the fuel system fuses to the wrong value in the past, so I'll start there.
Thank you for the suggestion