Another "cranks but no start thread"!

I've search about 3 hours and although I've found some useful information, nothing appears to be quite what I am experiencing.

I parked my 1995 with 260,000 miles at a second residence in April.
It has only been started twice during that time period, weak battery, but started nevertheless and idled about 5 minutes. Sunday (9/28) I decided to move the car to my main residence (75 miles away). Had to jump the car off (no surprise), but the car started and I drove about 5 miles to fill the tank up (it was near empty) I then drove another 5 miles and stopped for breakfast. Then about another 45 miles and stopped at a store. Another 10 miles and stopped at another store, then 4 miles to home. Car ran OK cruising, but had a mild rough idle. I did make it home nevertheless (75 miles). I spent the rest of the day cleaning the interior (Bad mold/mildew smell) and took a leaf blower to the engine bay to blow off leaves and rat dung. About 9 pm I started the car to make sure the battery was charged and it started fine. I turned it off and retired for the evening.

This morning I was going to drive the Corvette to work, but it strongly turned over and over, but no start. The only hint of fire was when I'd stop cranking the car, but these where only short stumbles. I tried starting fluid to no avail. Anyway, gave up and drove another car to work.

This afternoon, same thing. I checked fuel pressure. Good ~41 psi, held for 15 minutes. I checked codes and got 32, 34, 36, 38, 51 and 44.
I cleared codes and tried again and got codes 31, 33, 35, 37, (odd this time) and 74. I checked voltage/resistance at ICM and Opti and all checked out OK. Cleared codes again and after another no start attempt got only 74.

These codes make no sense to me.

I've narrowed it down to 4 possibilities:

1. VATS issue (I bypassed it 2 years ago out of necessity).

2. PCM is shot

3. Opti shot.

4. Bad/water in gas

However, I was able to drive it 75 miles yesterday relatively fine.

What are your thoughts?

Thanks!

 

Take a look at your fuel pressure regulator.

Also, after cranking pull a few plugs and see if they're wet.

It's somewhat strange, but then after sitting for six months, a good heat cycling might have had some effect on something. Really hard to say at this point.

 

Thanks for the reply. This morning the car started right up! I did not drive it. I plan to this evening.

One thing I did leave out Sunday: About the last 15 miles of my trip the Low Coolant light came on. I monitored both the analog and digital temp gauge and the temp got no higher than 230 °F. Hotter than normal, but a good ways from being in the 'red'. That evening I did added coolant. The overflow tank was completely dry and I added about 1/2 gallon in the radiator.

Point of this: I did remove the bleed screw and a small amount of coolant came out. It looks like the coolant from the bleed screw goes near/at the opti. Could it have gotten wet and now dried out?

I hope this is solved; however, I wish I knew for sure what has happened as I might not be so lucky the next time and my no start will not be on my carport, but miles from home, in the dark, raining, etc. etc.

As stated, my car has 260,000 miles. Should I go ahead and change the never been changed opti as preventative maintenance? I did change the water pump two years ago and it leaked and leaked all over the opti, but caused no problems then.

I understand the 1995 has an improved opti, but I'm sure it won't last forever.

 

Every single time my car has died since new the opti was at least part of the problem. If you are adding water then you are losing water and if it gets into the opti it's not the water killing it its the antifreeze blurring the pickup. Anyway at 260K I'd think it's about time for a new water pump and opti. I'm running an electric w/p now so no leaking on the opti just hope it stays running. You may find its the ign module or coil or bad opti connection but that opti deserves a rest. Since you bypassed VATS did you also bypass Passkey? I have bypassed both. I've tried every opti brand out there and none some to better than the other. Good luck

 

When was the last time the fuel filter was changed?

Also suggest checking all over engine bay for chewed wires since you reported cleaning out of rat dung.