When I turn the ac on and get to a stop the rpm drop to 0 and the car felt like it is going to shot down but with the ac off the car works fine . What can that weard symptom be?

Ps.I live in miami and is sumer so is really hottt

Tanks in advance

Before doing anything else, check for codes. Next, warm up car and set idle rpm to specs. Possible problem areas include:

. Air Conditioning Signal--this signals the ECM, when there is a demand for cooling from the air conditioning system. If the air conditioning signal is not OK, the ECM may need to be replaced. Try substituting a known-good ECM and recheck. If the symptom goes away, replace the original ECM.

. Idle Air Control Valve--clean or replace.

[QUOTE=txgreasemonkey]Before doing anything else, check for codes. Next, warm up car and set idle rpm to specs. Possible problem areas include:

. Air Conditioning Signal--this signals the ECM, when there is a demand for cooling from the air conditioning system. If the air conditioning signal is not OK, the ECM may need to be replaced. Try substituting a known-good ECM and recheck. If the symptom goes away, replace the original ECM.

. Idle Air Control Valve--clean or replace.[/QUO
So the ECU means Idle Air Control Valve?
How do I clean it?

Is this automatic or manual transmission?
Be sure your AC condenser fan is coming on with the AC.
Have you had any AC work done recently?

I haven't had any work done because it was woking fine
And is a manual transmission also the condenser fan works well

Does the engine stall as soon as you turn on the AC or only after the AC has been on for a while?
Does the AC cool at all?
Can you keep AC on by holding the RPM at 2,000 or so?
Is the AC condenser clean of dirt or leaves?
If you can keep the AC running with the RPM at 2,000 or so, check to see that water is dripping from underneath the car (towards the firewall - in the engine compartment) from a black drain hose.
If this evaporator drain hose is clogged it causes water to buildup in the evaporator housing and results in increased AC system pressures and exscessive engine load.
The drain can be cleared with compressed air.

FYI: Being a manual transmission your car has the better Idle Air Control Valve (IACV). They don't tend to stick nearly as often as the RACV style. It is mounted to the back of the intake manifold with two coolant hoses connected to it.

It would be beneficial to look at the ECU data with a scantool to try and determine what the ECU is doing and if things are operating properly. That may require a visit to the dealer. You may have a problem that can't be diagnosed without actually looking at the vehicle.

The engine stall after the AC has been on for a while
The AC cools perfectly
I think the AC condenser is clean but I'm not 100 %sure about the location of it
If I keep the AC running with the RPM at 2,000 or more the acceleration goes up and down until I release the accelerator and then is when the rpm goes really low almost to 0 and the car feels like is going to stall
Also I cheek the Idle Air Control Valve (IACV) but it looks OK ,someone told me that cult be the problem and that why should clean it but he didn't know how
If you don't know what else I can do I going to leave like that because right now I don't have money to take it to the dealer that's why I'm tying to fix the car like this like this

Tanks for taking the time to help me I really appreciated :)

It may sound silly, but you could remove the intake piping from the throttle body and clean the throttle body (while holding the throttle plate open). Buildup can cause a reduction in base idle speed.

I tried this and still te same.
From the description that I wrote before what else culd it be

Where is the ECM located and how do I clean the Idle Air Control Valve.
But I think you are right when you say is Air Conditioning Signal so what can I do??

(Air Conditioning Signal---) where is this??

What senser sends the signal to the ecm that the ac it running?