Buick/Olds: 1996 Buick evaporative system purge sylenoid, charcoal canister, solenoid valve

Question
Where is the evap sys purge syelnoid located on a 1996 Buick Regal 3800 series ?

Answer
I would test the purge flow solenoid valve and the purge vacuum switch in the engine compartment one of them is sticking and not allowing vacuum to flow to the charcoal canister at the rear of car. You can jumper power to the purge solenoid to see if it flows vacuum when ON. The switch is another story do not jumper power to the switch, it can be damaged. The circuit is current limited. Diagnosis might be a little tough without a Tech2 and an FSM. It sounds like you have already checked power and grounds at these two components. If you verified the circuits are good and the vacuum lines are all hooked up and not leaking then these two components highly suspected.

One more thing once you find the faulty component lightly tap it on a hard surface.
Check for the release of charcoal from either component. If charcoal contamination is present replace the EVAP Vapor canister, EVAP Purge solenoid, EVAP Vacuum switch and clean the EVAP purge hoses.