Town Car V8-281 4.6L SOHC (1991)
Fuel Pressure Regulator: Testing and Inspection
TANK VENTILATION INSPECTION
Testing Fuel Tank Ventilation System
1.
Check for broken seals at the filler cap, filler neck, the tank vapor vent valve, and between hose/tubing connections. Make repairs as necessary.
2.
Check the vacuum and vapor hoses for kinks, cuts, cracks, and blockage. Make repairs as necessary.
3.
Connect a hand vacuum pump to the fuel tank vapor vent line at the canister.
4.
Apply 2.5 inches of vacuum.
CAUTION: DO NOT apply any more than 2.5" vacuum. Vacuum should hold. If not, inspect hoses for leakage points.
5.
Open the fuel tank filler cap.
Applied vacuum at the pump should drop to 0 immediately. If not, inspect hoses for blockage.
PURGE SOLENOID TEST
Testing The Purge Solenoid
1.
Disconnect the electrical connector at the canister purge solenoid.
2.
Connect a vacuum pump to the source vacuum nipple of the solenoid, and apply 5" vacuum.
Vacuum should NOT leak. If it does, replace the solenoid.
3.
Connect jumper wires to the electrical terminals of the solenoid.
4.
While applying vacuum to the source vacuum nipple, energize the solenoid by connecting jumper wires from a 12 volt battery to the electrical
terminals of the solenoid.
The valve should open, allowing vacuum to pass through. If it does not, replace the solenoid.
