I have a 1998 Mustang GT with a 4.6 and 5 sp. Sometimes when the engine is started up cold, it will not idle at all. I can hold the throttle down a little ways and it will idle there. After running for a few minutes, it is OK. I have not did anything to it yet. Just wondering if anyone on here has had this problem.

 

try cleaning the throttle body

 

I have not tried anything yet. Will give that a try. Also, is the temperature sensor on these engines the same one for the computer and the guage?

 

is your check engine light on?

 

No, the check engine light has not come on. This is a problem that happened a few years ago and went away. Now it is back but worse than before. The car only has a little over 64,000 miles on it.

 

not sure about the '98 model 4.6 engine, but I do know on the 5.0 that the ECT sensor is not the same sensor that works the temperature gauge.

 

I would think there would be 2 sensors but all the parts stores around here just list one sensor and they do not show if it is for the guage or the computer.

 

theres your answer

pull the o2 sensors and clean them
do you have a K/N filter? if so clean the eletronic in the maf with brake cleaner as their might be oil residue on it

 

sometimes moisture can get in the intake air control module and freez causing it to not work properly until the motor warms and thaws it,If it not cold enough to do that it could be a temp sensor,but really there is no good way to diagnose this problems without the proper diagnostic computers. Otherwise it's really just a hit and miss kinda deal. Just because a certain sensor is acting up that doesn't mean it's bad.It could be getting the wrong signals from another sensor that is bad.

 

It could be IAC, but IAC problems don't usually go away after the car warms up. It sounds like you might have a MAM problem & it's collecting moisture.