When there is no vacuum, the EGR is closed. It opens when vacuum is applied . . but that depends on what engine and control system it has. When engines were carburetted, vacuum only determined when they were to open. But if a computer is involved, they determine when the vacuum signal is sent to the EGR.
Your EEC IV computer is definitely controlling when the EGR is open and when it is not. That is assuming that all the pieces to the system are functioning correctly.
For
a small yearly donation, you can support this forum and receive a 'Supporting
Member' banner, or become a 'Supporting Vendor' and promote your products here.
Click the banner to find out how.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.