Question about egr

The EGR system has a vacuum source (line from the intake manifold) that goes to the EVR, computer operated electronic vacuum regulator. The EGR valve and the passages in the heads and intake manifold route exhaust gas to the EGR spacer (throttle body spacer). The computer uses RPM, Load. and some other factors to tell the EVR to pass vacuum to open the EGR valve. The EGR sensor tells the computer how far the EGR valve is open. Then computer adjusts the signal sent to the EVR to hold, increase or decrease the vacuum. The computer adds spark advance to compensate for the recirculated gases and the slower rate they burn at.

The EGR shuts off at Wide Open Throttle (WOT), so it has minimal effect on performance. The addition of exhaust gas drops combustion temperature, increases gas mileage and reduces the tendency of the engine to ping. It can also reduce HC emissions by reducing fuel consumption.

Diagram courtsey of Tmoss & Stang&2birds


See http://www.veryuseful.com/mustang/tech/engine/ for more info

blacklxfive0 said:

I tried looking at that diagram earlier, but couldn't understand it that well. I think it's because a lot of the smog equipment was already taken off of the car by the previous owner. It's frustrating because I can't figure out where that tube goes.

Click to expand...

EGR vacuum routing:
One small tube from the back of the upper manifold (any vacuum connection port will do, not a critical item) to the EVR (Electronic Vacuum Regulator) on the aft side of the passenger side strut tower. One small tube from the EVR to the EGR valve on the throttle body.

If you still have any of the orginal vacuum lines left, the line from the Intake manifold to the EGR connects to a red line at the vacuum line coupler near the strut tower. The EGR valve connects to a green line at the same place.