Billz90IROC-Z

I pulled the vacuum line from the EGR valve, and I have no vacuum at all coming from the EGR solonoid.....does this mean its bad? Also, how difficult is it to replace the distributor module and pick up coil? Ive never done one before....thanks

Billz90IROC-Z

come on guys..........I need help.

Damon

The EGR valve does not MAKE vacuum. Vacuum is fed TO it when the ECM wants it to open.

The vacuum line starts on the bottom of the TB or the intake plenum if memory serves- it's been a while since I worked on a TPI motor. The intake is the SOURCE of the vacuum that is supplied to the EGR valve. From there it goes through a vacuum hose to the EGR valve CONTROL SOLENOID. This small black solenoid near the rear/passenger side of the engine has an electrical plug on the side of it that goes back to the ECM which tells the solenoid when to open and close electronically. When it's open it sends the vacuum down the other vacuum line attached to the solenoid TO the EGR valve to cause it to open. When it's closed it vents the vacuum to the atmosphere through what looks like a 3rd hose nipple on the side of the solenoid but which doesn't have a hose attached to it.

The ECM will only command the EGR valve to open when the engine is above a certain operating temperature and when it detects throttle position is somewhere in the part throttle range above idle speeds. Any other time (idling, WOT, cold engine) it won't open it.

Billz90IROC-Z

But shouldnt I feel vacuum from the EGR solonoid?

Chevero

This is the only time you could feel vacuum in the line TO the EGR valve FROM the EGR solenoid. Other than that, you can only feel vacuum in the line from the manifold to the EGR solenoid. In other words, there are two lines to the EGR solenoid, vacuum supply from the manifold, and vacuum sent to open the EGR valve. You will not feel vacuum in the line to the EGR because the car must be underway before the computer triggers the EGR solenoid.
Hope this helps.

Billz90IROC-Z

..........that is what I needed to hear.......that was perfect. Thanks for the facts...great straight forward understandable answer.......I appreciate it