I have a 1999 c280 with a m112 v6 engine. The car has been sitting for 3 years and im trying to get it road worthy again. First let me start with the symptoms i am having. I insert the key and there is about a 3-5 second delay before the engine actually starts to crank. It is cranking over pretty healthy but still does not start. Also if i let go of the key right after it begins to crank it continues to crank on its own for about another 5 seconds and then cuts off by itself. So the long list of everything i have tried. I changed the crankshaft position sensor twice, changed the camshaft position sensor, changed the coil packs, and spark plugs, changed the fuel filter and hoses, swapped the k40 relay for one that i know works, and i even testeda different crankshaft sensor wire, still no luck. Checked for fuel pressure, which was good. Checked for Spark found the spark plugs where not getting spark. I should mention when I removed the wire for the camshaft sensor the 5 second delay before cranking went away for a while and then came back. Also when i unplug the crankshaft sensor wire the engine still cranks over the same. Is the engine supposed to crank at all without the crankshaft sensor plugged in? when i pulled the spark plugs, they had a oil residue on the plugs and on the coil wire ONLY on the passenger side of the engine, the drivers side plugs were clean.. not sure what that could be. maybe from flooding the engine from trying to start it 50+ times?? Also i should mention that i have a complete running part car with same exact motor and specs that i have been using parts off of to help solve this issue. I am led to believe it is a electrical issue but not sure where else to look. any input would help, thank you