After a complete restoration, i have been hunting ghosts for two weeks. Im about to give up and tow it to a volvo specialist.

Initially it wouldn't start because pal cartridge fuses on battery terminal were blown (actually melted on the bottom, but looked good on top. I belived this was caused by a short in the driverside fuse area. One fuse had fallen and was shorting and burning at another.

After that, it started, but very rough, then shuts off almost immediately
It was throwing engine coolant temp sensor codes on ignition and fuel system.
I went through most fault testing and found what i thought were ground issues.

Still wouldnt stay started, and i was hearing loud exhaust leak from passengerside engine area. I had put on a new downpipe, but all seems connected well. When turning the crank by hand, i can hear hissing in that area.

Then i realized i was leaking oil at the oil pan front and rear. Despite new seprator box, seal, new flame trap, etc... I removed the seperator to clean out the drain pipe with a wire and wire brush.

Now i read on fcp site that too rich of gas could cause issues. The car had been sitting for 8 months while i was redoing everything i could. I thought i had drained the tank when it was parked, but then i realized it was the my other 240 which is in an early reconditioning with the tank out completely. When i put gas in it, It WAS NON-ETHANOL that i had for the lawn mower. I didnt even consider it would be a problem. I put about 4 gallons in it, but it was filled up then.

Any thought on the gas issue? Should i get it all out and put in new?
I had reconditioned the exhaust manifold by cleaning, removing rust and pits, and i never found any cracks.