i have a 1988 gxl NA.
*what should the intake vacuum be approximately at idle?
range from what to what...


using this img
http://www.geocities.com/huguesdc1/G...6-88vacuum.jpg
connect a vacuum gage to the red line at the intake manifold.

*Also, in what scenario does the EGR solenoid valve (yellow one) activate; close/open.

 

I remember when I was a kid, we used to set the engine timing to get the highest vacuum at idle we could. Usually advanced the spark by 10 degrees or so and we could get vacuums exceeding 18 lbs. Probably not good advice for a rotary. My RX7 produces 15-17 at idle. Anything less than 15 and I would suspect a vacuum leak somewhere. 18 is probably still a good target given good compression and properly tuned car otherwise.

 

when does the EGR solenoid valve (yellow one) activate; close/open.
under what circumstances?