car shutting off!

[94mustang0886]

hello i have a 94 base mustang, since i bought it the car musta be reved up for bout a mintute or too so it will stay on, basicly if i want to drive it i have to rev it until it stays on becuase if i just turn it on it will stall and rpms will fall and shut off, but once i started driving it it would be fine. now, when i am at a stop light and i am in D the car rpms will be around 700 ish and the engine will stutter and if i am stopped long enough it will stall and shut off!! VERY ANNOYING, i have had check engine light on since i bought the car i just prvouse owner tought it was becuase the fan was hoooked up to a direct switch but yeah does anyone know the problem here what senser or what might be out of wack, also what the check engine light could be, im guessing it could somthing with temp senser since it was replaced and fan is on a direct switch , can anyone help me!! i cant spend too much money on mechanics im a college student and my money is very tight . thanks

 

[MustangLX-5.0]

I would pull the codes for the CE light. Go to a local auto parts store. Many places will have someone come out and connect a code scanner for free.

As far as the low idle and stalling, it sounds like a bad or dirty IAC sensor (Idle Air Control). You can't miss it, its on the very top of the throttle body just after the air intake tube. Does it run better when warmed up? or is this all the time? First check to make sure the electrical connector is still plugged in. An unplugged IAC will cause the exact problem you're having. If it is plugged in, chances are that the plunger inside the sensor could be stuck.... most likely on cabon deposits, dirt.. oil etc. You can try cleaning it out to see if it resolves the problem. First, remove the nut and bolt the attaches the IAC to the TB. Now wiggle it a little bit (it can be stuck to the gasket) to remove. Get some carb or brake parts cleaner and spray into the 2 holes. Fill it up with cleaning agents then plug the 2 holes and shake it around. This agitates the solution and helps loosen more deposits. After about 30 seconds, dump the stuff out. Spray in a couple more times and repeat. You may want to wear gloves if your hands are sensitive. After a few times of this, shake it out good and dry with a clean rag. Re-install and then plug in electrical connector. Start engine, the first time it starts it may be rough from the cleaner fumes. Your engine should idle within 1500 RPM's at first, then after about 30 seconds to 1 minute it should idle down to around 700 - 800 RPM. If it still idles low and stalls, then the IAC is most likely faulty. If you get a new one, DO NOT buy one from Autozone. I have heard one too many complaints from defective IAC's boughten there.