Haunted by the EGR...

[Markus]

There should also be a vacuum solenoid valve. This would be before the regulator. It turns the vacuum on and off.

At idle the vacuum solenoid should be off and there should be NO vacuum going to the EGR valve. As engine speed increases the solenoid comes on and then regulated vacuum is fed to the EGR valve.

The DPF EGR sensor calculates the flow of exhaust gas solely as a check for actual EGR valve operation.

Here is some boring reading....

http://www.asashop.org/autoinc/dec97/egr.htm

Paul, from the 95 Helm book:


DL98 Check EVR Solenoids For Shorts
An EGR Vacuum Regulator (EVR) solenoid or EVR driver circuit short could cause the EVR to open supplying the EGR valve with vacuum.
• Key "OFF".
• Disconnect vacuum hose at EGR valve and connect hose to a vacuum gauge.
• Run engine to operating temperature and stabilized idle.
• With the engine at idle, tap the EVR solenoid and wiggle the EVR connector while noting vacuum reading.
Does the EGR vacuum remain below 3.4 kPa (1.0 in Hg) with no sudden increase?


NOTE: EVR leakage below 3.4 kPa (1.0 in Hg) is normal



Yes Leave vacuum gauge connected. Go to DL99 - Check EVR Harness Circuit For Intermittent
No Inspect EVR solenoid connector for shorts. Service as necessary. If OK, service or replace EVR solenoid. Reconnect all components. Clear continuous memory. Rerun quick test.