[pamper2]

I have verified solenoid is good. I have 12 volts to solenoid but the switch that completes circuit is in ecm. I have replaced ecm. My info states that "to close switch 1.the vehicle must be operating temp. 2. throttle above idle 3. MAP"

... any info will be appreciated.

[CaptainRich]

The exhaust gas recirculation (EGR) system allows a small amount of exhaust gas to flow from the exhaust manifold into the inlet manifold when the throttle is opened beyond idle and inlet manifold vacuum is normal. This reduces combustion temperatures in the engine to control oxides of nitrogen emissions.
The EGR system used with gasoline engines remains closed during periods of engine idle and deceleration to prevent rough idle from excessive dilution of the air/fuel mixture. It also remains closed at wideopen throttle to prevent power loss. At other times, it rapidly cycles open and closed to modulate the flow of exhaust gas as required. Under certain circumstances, it may remain fully open to provide the maximum EGR.
What is your specific issue? Is the check engine light on? If so, what DTC is being set?
Is the EGR staying opened? Closed? Inop?

[pamper2]

No, I have never had a check engine light, no codes. My vehicle won't pass emissions because of high HCs and high NOX. I have given it a full tune up, cap, rotor, plugs and wires, pcv, and oil change. In checking my egr circuit I noticed with vehicle warmed up good, when I give it throttle there is no vacuum between the vacuum solenoid and egr... so of course the egr will not open. I have 12 volts to the solenoid, but (checking the schematic) the switch completing the 12 volt circuit from solenoid is integrated in the ecm. My manual condemned the ecm so I have installed a new ecm with the same result. My question is do you know what signals the switch inside the ecm to close, which must happen to energize the vacuum solenoid ? It must be something other than just the coolant sensor and the throttle position sensor. Thanks.

[CaptainRich]

I don't know what manual you're using so I don't know what criteria would condemn the ECM. Unless there is a hard DTC, I would have a hard time replacing the ECM.
I'd tend to lean toward a sluggish catalytic converter as the culprit.
Being a '94, especially with TBI, I know that "cat" has been very busy.
Another problem with many emissions testing facilities: vehicle's are sitting for too long before they are actually tested. This allows the converter to cool off significantly, thus rendering it unready to perform it's converting.
Ask if you can have the HC and NOX tested again, but before you step up for "the sniff", raise the idle for a few long moments to reheat the converter so it will be primed for operation.
Another good tip would be to make certain the PCV system is functional and you have a fairly recent oil change. Contaminated engine oil can increase substantially the amount of hydrocarbons that have to be consumed before leaving the tailpipe.

[pamper2]

Thanks.