I have a 94 cavalier rs 2.2 and when i start my car it idles really rough and the car will shake and yu can smell gas. It goes away when i drive away or push the accelerator. I replaced the 02 sensor air filter fuel filter air temp sensor. I replaced the plugs and wires with ACCEL and when i changed the the spark plugs had white powdery stuff on them.

it is probably an injector. the are really common for having a problem. sometiimes it is just the o-ring on the injector that will cause them to leak but you are better off to just put new injectors in if you have to take the fuel rail off

could be a stuck egr valve as well as other things too

Also check the IAC they are also known for getting gummed up and in ur case it isn't moving which is causing a too lean or too rich mixture and that could be the gas smell. Remove it and clean it.