Car wont hold idle all of the sudden!

[98laseredgt]

i drove my car to work today at 6am. ran fine, started right up and idled smooth at about 800 rpm. i turn it off at work and go to leave at about 10:30 and the car wont idle and keeps dying. i been meaning to put the new plugs in. so i go home and let it "run" in my parking spot (apt. complex). and it idles at like 400 and drops to 200 and picks back up. like a cam only not. i checked all the vacuum lines they all looked fine but there is a loud hissing coming from around the upper plenum at idle, it goes away when you open the TB. so i turn it off and change the driver bank plugs, the back 2 had oil, clean oil, in the hole all over the plug, but not the cumbustion chamber, and not on the threads. i checked my oil, it hasnt been leaking and i dont think its burning because my exhaust exits right before my bumber and there is no oil residue on the bumper or in any of the tips. somehow the oil is not even showing on the dipstick. about 2100 miles after the oil change. i put in 6 quarts when i changed it too. there is no oil on the motor other than the 2 plug holes where i found it, and in the number 8 plug under the boot, i found a little metal piece like something that holds the bumper on. after i did all that i let the car sit with the battery disconnected for a bit and started it up. still idles bad and hisses. but no codes after i let it sit for about 2 minutes running. it has idled rough before, but if i hold the gas at about 1100 for a few seconds and let off it will go back to normal. that didnt happen this time. i have an off-road h-pipe and no MIL eliminators but that hasnt been a problem for 2100 miles (about a month) could that be the problem? anyone have any ideas?

 

[bdcardinal]

it is the IAC ( Idle Air Control) solenoid. you can clean it with some throttle body cleaner for a temporary fix, however you will eventually need to replace it.

 

[StangLou]

The problem does sound like your IAC, but I dont recall ever hearing a bad IAC "hiss" like he is talking about. You can try to clean it, and see if it works I guess. Sounds like you have a vaccum leak somewhere though since you are hearing a hissing sound. Have you done a tb/plenum combo? If so was everything tightened back up correctly???

 

[scooter6753]

check ur MAF...sounds like its dead....also check to make sure ur filter is on tight and the back end of ur MAF is connected. I just fixed the same problem with mine.

 

[KaPPaBaLL]

clean both of what these people said.

 

[98laseredgt]

problem fixed, it was the IAC. the hissing was just the intake i guess, it still does it but all the lines are connected and everything is tight. i also changed the fuel filter and PCV and plugs while i was at it. thanks for the replies guys.

 

[new22003]

Wonder if ford will ever fix that damn IAC. Gone out twice on the wifes car already.