I have 95 ford t-bird 4.6 when idling around 600 rpms when shift , or give gas it hesitates. i believe idle air control valve?? i have cleaned egr valve and no vacuum leak also new tps whats your take on this.

It could be a software problem has set the idle too low or there could be a minor engine fault, blocked breather maybe or sticky egr valve.

Often this sort of problem is caused by a sticking idle air control valve or blocked or partially blocked air ports.
A can of carburettor cleaner can be used along with a stiff paintbrush and a compressed airline to clean around the throttle butterfly, the breather ports and idle control valve; removing parts as required.

IAC valve may need to be cleaned but it would not idle corectly if so . look for holes in tube going to throttle body . also have you replaced wires and spark plugs ?

Has it ever been tune up,

sounds like low idle control sensor ! when car acting up could sstop by parts house get them to plug computer in and see if any codes have been stored even though the engine light not on at this time

pull wire off # 2 see if idle changes if not there s no spark... test coil....test all vacuum lines for leaks also. if all good then idle speed sensor.

You are going to need to start with a new idle air control valve. It is mounted on the throttle body on top of the engine.

Check EGR valve this controls idle speed it might have carbon build up hold the valve open. All so check fuel pressure.

if it isnt the iac probably the pcv valve positive crankcase vent. it is on a vacuum line somewere under hood. or check the air cleaner, the hose with the small filter underneath the air filter. i take its fuel injected?

Zab, First things first, check for any vacuum leaks, hoses that are disconnected, cracked or just plain worn out. Also check for vacuum leaks around the throttle body.
It really sounds like you have an EGR valve that is stuck open ever so slightly. The MAP sensor is a result of a low manifold vacuum. The IAC (idle air control) motor is trying to compesate and keep the engine running resulting in the high idle speed. I would remove the EGR valve and clean it gently with a brush and pick to remove any carbon build up.
Let me know, regards.

I figured out what was going on. supposedly on ford rangers the Idle Air Control Valve (IAC Valve) goes bad. i got a trouble code looked it up and sure enough it is the IAC Valve. Under 100 bucks for the part