Whats wrong with my '01 Pontiac Grand Am?

[filbert910]

My car has had a very rough idle for a bit. Now the car wont start unless i start to give it gas as i start it. The idle is still very rouch and often shakes the whole car when i'm at a stop light. It makes a 'clunky' sound when idle-ing (kinda sounds like those old steam engines) I've changed the oil and had a fuel injection cleaning done.
forgot to mention. i opened the hood while it was running the other day and heard a hiss coming from the engine area. dont know if that helps.
also, i've changed all my spark plus and cables.

 

[kmp1171]

OMG why do people answer always say take to shop if wanted to do that would ask here. Any you have 1 maybe 2 problems Firts of all find that hissing and fixit its a vaccum leak if cant fine by sound take can of brake clean and spray section of engine when u spray spot and engine idle changes theres leak fix it. check for more than one . after you do that
does it run ok or not if no and u r sure you found and fixed Vaccum leaks check fuel pressure... below 40psi bad.. if need more info email me

 

[Metallman56]

a hiss coming from the engine is probably either a vacume leak. if you dont have a serive engine soon light on, then id take it to a mechanic you trust. it also kinda sounds like you might need a mass air flow sensor, as mentioned above. air getting into your engine that not coming though your MAF, will cause your car to put less fuel then it needs into the engine. which could explain why you need to give it more gas.

good luck