Cadillac Repair: timing info, aldl connector, solinoid

Question
i have a 1990 deville with a 4.5....emissions sticker isn't on the car so what i need is the base timing spec and the procedure...mainly where is timing pigtail location or does one put car into diagnostic mode to set timing...if so need refresher on that procedure..also one other thing...does egr solenoid operate with vehicle not in gear?just failed az.emission test because of slightly high nox reading...egr failure...valve works with direct vacuum but  with solenoid connected doesn't work...am buying new solenoid tomorrow...thanks k.r.

Answer
Hi Ken, The timing is set by jumpering A to B on the ALDL connector. It is located under the dash below the ashtray area through a rectangular hole or plastic flap/door. With the engine warmmed up so the thermostat is open it should be 10 degrees BTDC. As for the solinoid it has vacuum and power to it all the time and the computor controls the ground side of the solinoid. What happens is the solinoid will leak vacuum causing the egr to open or flutter  at idle or the egr valve spring gets weak and it can't stay closed at idle. The valve works with the engine at opperating temp. and the engine accellerated off-idle. It can be in park or drive to open. Sorry for the late responce. Hope this helps. Bill