BlueDemon

hey guys and gals,I just have a questionabout my stang. When I start my mustang after I've been driving for a while and it's at normal operating temp it seems to idle erratically--almost to the point of choking out. If I lightly tap the accelerator and hold it for a few seconds it will idle fine. It's not overheating that much I know.Butcould it have something to do with a idle sensor or somewhere along that line? Also shouldn't I have pressure in my radiater after I've been driving for awhile? I bought a new pressure release radiator cap and if I open it up after a long trip there is no pressure escaping from the radiator-- its as if I didn't drive it at all!! There is no coolant leaks any where and my heater works excellent.Any advise or help you can give me would be greatly appreciated. THANKS

mdvaldosta

Lots of things affect how much pressure is in the radiator, and you want SOME pressure. Make sure your cap is tight, without any pressure in your cooling system you will slowly loose coolant (assuming its leaking pressure somewhere most likely the cap) and the car won't run as cool. If in doubt many places can do a coolant pressure check and check your radiator cap for low bucks.

As for the stalling issue, what year mustang do you have? The most common idleing problem, even on 2 year old stangs, is the IAC, or idle air control valve. Its located on the side of the upper intake plenum and often gets carbon buildup inside and that causes the pindle inside to respond slow or get stuck. Take it off and spray out the inside with carb cleaner, then spray it out again with brake cleaner to remove any residue left from the carb cleaner. That will fix 90% of all idling problems.

BlueDemon

mdvaldosta, thankyou for the advise. I tried what you told me about the IAC and it worked great--you sound like you really know your stuff!! As for the pressure in my radiator I took it to Auto Zone and they tested the pressure in the radiator and there was no pressure at all. They pumped pressure into the radiator and when they did that it held the pressure and it didn't lose any of it. So basically i'm back to square one. Could it be that there might not be a thermostat in the housing and thats why I'm not getting pressure in the radiator?? I know that probably sounds stupid but I'm pretty much grasping at straws. By the way my stang is a 88 lx 5.0 and I've owned it for about a year now. I've pretty much changed everything to do with the cooling system except I haven't touched the thermostat housing or the thermostat(if theres one in there)since I've had the car. It has a new radiator,water pump,all hoses and fresh antifreeze Again thankyou for your advise and help--your a gentleman and a scholar!!