EGR Control Switch & EGR Valve?

[Alan_nc]

94 Ranger, 3.0, Auto
The EGR control switch has two tubes coming off the bottom portion of it.
One goes to the EGR valve.
Are either of these vacuum lines?

 

[RonD]

Both are
One goes to the EGR Valve
The other goes to a Vacuum source, like Vacuum reservoir hose

That's the EGR modulator/solenoid, computer uses this to open EGR valve a little or alot by pulsing its voltage, it has 2 wire connector


Then there is an EGR Sensor, DPFE, it also has 2 hoses but they are not vacuum hoses, they run to the EGR Tube, its between exhaust manifold and EGR Valve
DPFE reads pressure difference in the tube when computer opens the EGR Valve, so computer can "see" the amount of exhaust gases that are flowing into the intake, it has a 3 wire connector

 

[Alan_nc]

The tube that goes to what I am calling the EGR valve (pot with single pipe coming directly out of the top of it). This tube on mine has no vacuum at all when engine is up to temp and idling.
The black plastic unit on the other side of the intake manifold (with two tubes coming off it's lower portion) (one going to the EGR valve) has no vacuum on either line.

 

[RonD]

EGR system is off line at idle cold or warm, no vacuum at EGR Valve

Its only used to stop a spike in temperatures when accelerating or cruising


One hose on the EGR modulator/solenoid, should have vacuum when engine is running
The other hose goes to the EGR valve

So if that hose doesn't have vacuum its unhooked, or broken, follow it to find out which

 

[Alan_nc]

Thanks for the information.
Once I had all the tubes sorted and plugged in good and tight I had vacuum (about 19) on the lower of the two tubes.

 

[RonD]

Good stuff