LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 1999 >> Contour SVT >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing - EEC-V >> Fuel System (Natural Gas Vehicles) >> Leak Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Leak Test

NOTE: After vehicle has sat for several hours, a very slight natural gas smell may emanate from within intake manifold and intake air system. This is a normal condition. After several hours, fuel injectors leak down.

  1. Fuel Rail & Fuel Injectors

    Turn ignition off. Remove Fuel Shutoff Valve (FSV) relay from power distribution box in engine compartment. To pressurize fuel system, connect a jumper wire between FSV relay socket No. 87 and 30. See Fig 1-Fig 3 . Remove jumper wire and reinstall FSV relay.
    NOTE: To identify Fuel Shutoff Valve (FSV) relay terminals, refer to numbers molded on relay. FSV relay is also referred to as fuel valve relay.
  2. Using leak detector provided with Natural Gas Vehicle (NGV) Pressure Test and Vent Kit (134-00114), check for leakage at spring lock coupling and fuel rail-to-fuel injector connections. If a leak is detected, repair as necessary and retest.
Fig 1: Connecting Jumper Wire To Fuel Shutoff Valve Relay Connector (Crown Victoria)
G99D02864
Fig 2: Connecting Jumper Wire To Fuel Shutoff Valve Relay Connector (Econoline)
G98G00345
Fig 3: Connecting Jumper Wire To Fuel Shutoff Valve Relay Connector (Pickup)
G98F00344

  1. Fuel Tanks & Fuel Lines

    Verify fuel tank pressure is at least 1500 psi (10,343 kPa). If fuel tank pressure is less than 1500 psi (10,343 kPa), refuel vehicle. Using leak detector provided with Natural Gas Vehicle (NGV) Pressure Test and Vent Kit (134-00114), check for leakage at fuel tank(s), coalescer/filter and fuel lines. Coalescer/filter is located inside of left frame rail. If a leak is detected, ensure fuel line fittings are tight and retest. If leak is still present, inspect "O" ring ,"O" ring land and sealing surfaces for damage distortion or contamination. Repair as necessary and retest.

  1. Upper Fuel Tank Rack Vapor Vent Box (Crown Victoria)

    Connect Rotunda Pressure Test Adapter (134-00122) to upper fuel tank rack flexible vent tube. Pressure test adapter is part of Natural Gas Vehicle (NGV) Pressure Test and Vent Kit (134-00114). Pressurize vapor vent box to 17 in. H2 O. Monitor pressure for 2 minutes. Pressure should not drop more than 6 in. H2 O. If pressure drops more than 6 in. H2 O, apply a soapy water solution around vapor vent box gasket and seals to pinpoint leak. Replace gasket or seals as necessary. Retest system.
scientia non olet · About LEMON Manuals