Hello group,  my new to me.  92 100Q with 2.8 as a nasty vacuum  problem to
the EGR,  the EGR valve is working properly as I have checked with a
external vacuum pump and it stalls engine.  When car idles there is no
problem and also no vacuum to the EGR.  When I put revs to the engine vacuum
builds to the EGR holds it open but upon return to idle position the vacuum
solenoid reg does not release the vacuum to the egr so the engine stumbles
and idles like crap...  I check the ohm resistance to the solenoid valve and
there it checks out with spec.    I also check the idle switch continuality
at the TB and that is OK also..  Please anyone have any other checks without
spending Big bucks at the Dealer..  Yes the engine light comes on as I am
cruising along and stays on until I shut car off..Engine light stays off
until I am back on highway.  This is with the EGR disconnected from the
vacuum source and with the vacuum hose plugged.  For now this is the only
way I can get the car to run smooth enough no to hurt it.     Please help!!
Thanks in advance