I have an 89 Formula and have been having problems with the engine surging and not idling properly. Sometimes the car runs fine but more so it has the problem. The car sometimes shuts off when going to stop. Recently gas was coming out of the vent on the canister purge solenoid and when i opened the gas cap there was a good bit of pressure but when i released it the gas stopped flowing out. Any ideas on what could be causing all of this.

 

Check your fuel pressure at the fuel rail.