1994 Geo Prizm Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Fuel Pressure

NOTE: For fuel pump specifications, see FUEL PUMP PERFORMANCE  .
  1. Release fuel pressure. See FUEL PRESSURE RELEASE  . Disconnect negative battery cable. Remove bolt and fuel inlet hose from fuel rail.
  2. Install Adapter (J-39802) with gaskets and fuel inlet hose to fuel rail. See Fig 1 . Tighten adapter retaining bolt to 22 ft. lbs. (29 N.m). Install Fuel Pressure Gauge (J-34730-1A) to adapter.
  3. Reconnect negative battery cable. Turn ignition on. Connect jumper wire between Data Link Connector (DLC) terminals B+ (Black/Red wire) and FP (Blue/Black wire). DLC is located on left strut tower. Check fuel pressure. See Figure or Figure . Release fuel pressure. Remove fuel pressure gauge. Remove jumper wire from DLC.
Fig 1: Installing Fuel Pressure Gauge
G93E78471Courtesy of GENERAL MOTORS CORP.
FUEL PUMP PERFORMANCE

Application Pressure: psi (kg/cm2 )
Prizm & Prizm LSi (1)(2) 38-44 (262.0-303.4)
(1) With ignition on, engine off, and jumper wire connected between DLC terminals B+ and FP. DLC is located on left strut tower.
(2) With engine idling, jumper wire removed from DLC and pressure regulator vacuum hose disconnected and plugged. Reconnect vacuum hose. Pressure should decrease to 31-37 psi (213.7-255.1 kPa).
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When to See a Mechanic

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

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