So here is the deal. Took my car into the mechanic beacuse it was idiling real high my guages dont work but probally idiling around 2 grand. So after replacing a fuel air sensor car ran just fine. Mechanic told me i needed new battery. next morning car starts fine but two hour later car turns over but idles hella shitty and i have pretty much tranny drop from nueatral to get it to run but runs fine once moving. So take to mechanic another two days in the shop. he replaced the battery an engine cooling sensor and a fuel filter and adjusted the throttle picked up the car ran fine. 20 minutes later car wont start call mechanic he says wait 5 minutes try again it starts fine and runs fine ever since then its like a gamble when i start my car. It will either (A) Not start at all just crank (B) turn over but die out right away (C) start and idle rough but after 30 seconds or so sound fine or (D) Start and run just fine. No matter how it starts if it does start and run it sounds perfect and runs fine no rughness when i come to a stop or put it in nuetral. So thats where i am at any input would be super appreciated

 

what year car with what engine?