1990 Geo Storm Base, StandardFACTORY OEM SERVICE PROCEDURE

Fuel Pressure Test

  1. With engine off, relieve fuel system pressure. See FUEL PRESSURE RELEASE in this article. Attach Fuel Pressure Gauge Set (J-34730-1) and Adapter (J-35957-10) at outlet side of fuel filter. See Fig 1 . Reinstall fuel pump relay. Crank engine a few times to build up fuel pressure to 35-42 psi (2.5-2.9 kg/cm2 ) to start engine and check for leaks.
  2. Note idle fuel pressure should be 35-42 psi (2.5-2.9 kg/cm2 ). Turn engine off. Disconnect and plug vacuum hose from pressure regulator. Turn ignition on. Fuel pump should run about 2 seconds and fuel pressure should be holding 35-42 psi (2.5-2.9 kg/cm2 ).
  3. Start engine, reconnect vacuum hose, and note fuel pressure drops slightly. Next, pinch off fuel supply line at flex hose momentarily and note fuel pressure. Maximum fuel pressure (fuel line pinched) should be above 65 psi (4.5 kg/cm2 ).
  4. If pressure is not within specification, check for defective fuel pump, pressure regulator or restriction in fuel system. Repair as necessary. Remove pressure gauge and adapter. Start engine and check for fuel leaks.
Fig 1: Testing Tracker Fuel System Pressure (Storm is Similar)
G121592Courtesy of GENERAL MOTORS CORP.
REGULATED FUEL PRESSURE

Application (1) Pressure psi (kg/cm2 )
Storm & Storm GSi 25-30 (1.7-2.1)
(1) With ignition on, engine idling and fuel pressure regulator vacuum hose connected.
UNREGULATED FUEL PRESSURE

Application (1) Pressure psi (kg/cm2 )
Storm & Storm GSi 35-42 (2.5-2.9)
(1) Check with engine idling. Disconnect and plug fuel pressure regulator vacuum hose.
MAXIMUM FUEL PRESSURE

Application (1) Pressure psi (kg/cm2 )
Storm & Storm GSi More Than 65 (4.5)
(1) Fuel line pinched before inlet to TBI or fuel rail.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.