Alot of the symptons I am having are the same for EGR valves as they are for faulty fuel injectors. If you step on the gas fast and hard, you get a lock and nothing. It's either getting flooded, or not getting enough fuel or pressure (I just don't know). If you are sitting at a stop sign or light, it will stall from idling. The problem gets worse as it warms up to normal temp or beyond. If the car is too warm and had been running for a while it may not even start back up for a while. I had taken it to a shop and they said I had a vacum leak that caused a clogged Catylitic converter. So the converter and the PCV valve were replaced with new ones but the problem STILL exists.

Now I am about to disassemble down to the manifold, and since that is the only time I wll be able to get to the EGR Valve, I figured it's time to test it. But I am clueless as to how to figure out if the EGR valve is the problem.

How do you test the EGR valve and diagnose whether it is malfunctioning?

 

apply vacuum to the valve with a hand vac pump with the engine running and the idle should drop. also make sure the valve will hold a vacuum. if you can lift the diaphragm by hand try that to see if its stuck.

 

How would I lift the diaphram? The entire EGR looks like a big solid piece of medal to me, with the exception of the tube where the hand pump can plug onto.

 

if you can't access the diaphragm the vac test is all you can do. you can ohm the injectors. around 16ohms. fuel pressure should be 38-48psi. closer to 48 though.