Does vacuum open or close EGR?
Gasoline EGR valves divert the exhaust gases, much like the high pressure diesel equivalent. Vacuum operated EGR valves use a vacuum solenoid to vary the vacuum to the diaphragm and, in turn, open and close the EGR. Some valves also include a feedback sensor to inform the ECU of the valves position.
What happens if EGR is stuck closed?
If the EGR system is clogged up, or the valve is stuck closed, the combustion temperature increases. This may cause pinging (detonation), as well as surging on light acceleration. In a diesel engine, a bad EGR valve is one of the causes of a black smoke.
How to check for vacuum at the EGR valve?
If you have a scan tool capable of controlling actuators or pids you can command the EVR on and check for vacuum at the EGR valve as the regulator opens. If you do not notice vacuum at the EGR valve as the EVR is commanded on and you do have supply vacuum at the EVR connector then check the EVR,…
Why does my dpfe have a leaking EGR valve?
You now know the DPFE, EGR valve and tube and hoses are okay and we can move on to test the EVR (EGR Vacuum Regulator), part of the system. If the reading did not change, then you could suspect a leaking EGR valve, allowing uncommanded flow of exhaust gases.
What causes excessive pressure in the EGR valve?
If the reading is higher suspect a restricted exhaust system to be causing excessive pressure. If there is no flow, then suspect a restricted EGR tube below the hose connections. I have also seen once, that the orifice in the tube seperated so there was no pressure difference in the hoses when the EGR system was flowing.
How does the EGR system in a car work?
So what is an EGR system and how does it work? EGR stands for Exhaust Gas Recirculation, and as its name implies, this system allows exhaust gasses from your car to be re-circulated into the engine, helping to reduce emissions.