Im in need of some advice....
my 93 Accord EX isn't passing SMOG and I have traced the issue back to the EGR valve not staying open. I have put a vac gauge on it and is only getting vac for a brief moment when I rev the motor, then it goes to zero, closing the EGR.
I have diagnosed the issue back to the electric proportioning valve on the firewall in the black box along with various other vaccum lines that go the the intake manifold. I have found that the electric proportioning valve is also only getting voltage when I rev the motor than too goes to zero.

My question is, where does this electric motor get its voltage from?? Does it come directly from the ECU?? If so, are there other sensors that might cause the output voltage to the EGR proportioning valve to be intermmitant?

Thanks a million,
-S