Some context to this headache. My friend's car is completely stock and has about 142k, and had sat for some time. When we were getting around to getting it back on the road, we did a tune up (plugs and wires) and found we still had a misfire. Found out that Cylinder 1 Fuel Injector was not working and changed it out for a new one. Ran awesome. Over time, found out the car was flooding, bad. Was so bad that smoke poured from the exhaust as well as what seemed to be oil being sprayed out. It was bad enough that the fuel leaked into the crank case oil and would shoot out of the PVC system if you revved it up and into the intake and even prevented the car from cranking a few times. It flooded the lower intake and the car could literally run forever without injectors hook up. I took the fuel rail off, replaced all of the orings, and hooked it back up minus putting it on the intake manifold and pressurized it. 0 leaks. Drained everything out of the pan and flushed it out with some oil and put about 5qts back in it. Ran great, other than the fact the smoking was still there, but I am assuming it is possibly because of the oil/fuel mixture that might still be in the exhaust system and is burning.
For the smoke, I'm sure it isn't coolant because it definitely does not smell like it and the car does not over heat. I am pretty sure the rings are fine because I did a compression test before I fixed it the first time and everything tested almost identical. I don't remember exact numbers, but I think it was around 120-150psi. My friend has been driving it for a few days, but two days ago he said it wouldn't start. We jumped it last night and got it home, but I noticed it was misfiring. I looked at it today, and it was not starting because it was doing the same thing as if it was flooded again. I unplugged the injectors and got it to crank enough and finally start and it even ran for a few seconds before dying. I plugged everything back in and it fired right up, but was still misfiring. Cylinder 4 is misfiring and I am pretty sure it flooded enough to mess up the spark plug. I have not pulled it yet, but that's my thought. There is what seems to be oil on part of the intake filter as well. I pulled the PVC hose, started the car, and revved it to 4k a few times and nothing came out.
I am not sure where else to go on this. I have not checked codes, but when it was doing this before the only code it gave was the knock sensor, but I replaced the sensor when I cleaned out the intake. No check engine light on currently. Could back-pressure in the exhaust system be putting what is still in the exhaust system back into the cylinder? There was so much in it at one point it was dropping out of a flange piece.