I can't find the IAC valve in my 97 ford expidition 4.6l v8, & I don't know what it's looklike either! can anyone be of help? Tnx a lots!!

IAC valve. Cheap, easy fix. Any auto parts shop has them on the shelf. Autozone, O'Reilly, Napa, etc.

try to clean your iac valve.

There are three engines used in a 97 model. The 4.0 single overhead cam V6 engine uses a timing chain in the front and in the rear, one for each cam. The left side is in the front and the right side is in the back. You would have to take the engine out to access the rear chain.
The 4.0 overhead valve engine and the V8 engine only have one chain in the front.

There is a mod for this problem. Insert a 1/2" copper pipe cap with a 1/4" hole drilled in the cap, into the rubber IAC pipe. This restriction helps fix high idle and thumping from IAC valve. Ford has a "muffler in line" fix for this issue, but for a $.50 copper cap, why give $50 to Ford engineers.

Don't know if you already solved your Mustang's problem...the Idle Air Control (IAC) valve could be dirty, or if not cleanable not to costly to replace...a vacumn leak would be a more consistent problem...your local parts store can help you with the location of the IAC. Hope this helps.

the IAT sensor or the IAC valve! is the idling messed up. if so remove and clean IAC and if no differance replace it. At the throttle body and will look like this

it has a iac ( idle air control valve ) to regulate the idleing. it may need to be cleaned or replaced. good-day!! just remove and clean IAC it may help a lot.

I would suspect the IAC (Idle Air Control) valve, A O2 sensor or egr valve isnt going to have any effect on idle.

I.A.C sit in top on T.B.I. it's held on by two 8mm bolts, remove bolts clean surface replace gasket and reinstall sensor.

idler control valve or Vaqium leack