EGR VALVE 1994 F-150. Pinging is caused by ignition timing being to advanced, it is because the fuel is buring way too fast and causing a detination. Also it could be caused by a lien condtion, when chamber temp get too high. One other item is overheating will cause pinging. The egr will not cause this. Checked the voltages on the 2 pins of the harness for the EGR side and had a reference voltage of 12v and a constant 4ish volts for the controll pin. When I checked the harness connector of the VGT solenoid it had the 12v reference but the control pin was jumping from 0 to 4 and dropping strait back to 0, the sequence was 0,2,3,4,0. 2008 Ford Explorer Ltd. May 24, 2017. #6. tripplec said: Its not the first engine to not have and EGR valve. I had an iron block 4.0L I6 (inline) in my Jeep Grand Cherokee 2002. No EGR valve. In my opinion this is good as not carbon and sticking issues or vacuum problems for it to work. Received 157 Likes on 125 Posts. And to answer your original question, EGR valve should be normally closed. There should be no vacuum delivered to the EGR valve by the EVR at idle or wide open throttle. It functions during part throttle, low load situations. The EGR system has a vacuum source (line from the intake manifold) that goes to the EVR, computer operated electronic vacuum regulator. The EVR is located on the back of the passenger side shock strut tower. The computer uses RPM, Load. and some other factors to tell the EVR to pass vacuum to open the EGR valve. SPnT.