Me and my brother fixed the valve cover gasket on my car friday. When he took the head off the engine, he said that somehow oil spilled into one of the spark plugs, we also put new spark plus in.After we finished we tried to go out, but when we started the car it made a loud backfire noise. Then when we put it in reverse, it started shaking A LOT and moving very slow, and it was making like a popping noise. My brother said the oil needs to burn that spilt, but I wasnt sure because the car really takes a while to speed up and shakes a lot. And when I drove it on Saturday, the car was hesitating to speed up and the fastest I would get to is 55, on the freeway. And today, the car just won't start, it keeps cranking and cranking, but I get nothing. And last but not least, I noticed on one of the hoses that there was a leak, and when I smelled it, it was gas. So if anyone can help me here or give me and idea of what I can do to fix the car, let me know.

 

Did you replace the spark plug tube seals as well? If youonlyreplaced the Valve Cover gasket you'll have mismatched "deck height" of the seals, and might be Dumping oil into the spark plug wells.
Fix the hose that is leaking gas.
be sure the plug wires are on correctly?
oil does not conduct electricity, so if oil got on to the plug wire connector, it can cause misfires.

 

Yes I did relace the spark plug tube seals and the plug wires are in right. My brother was able to get the car running last night, but while it was running I noticed a nosie, I was told its a vaccum leak.