Fuel Pressure Check
WARNING: This page is about a different car, the 1990 Subaru XT6, 1990 Subaru XT, 1990 Subaru Loyale, and 1990 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.
Basic diagnosis of fuel system should begin with determining fuel system pressure. If fuel pump is inoperative, see appropriate FUEL PUMP CIRCUIT TEST CHART in this article.
WARNING:
ALWAYS relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT
allow fuel to contact engine or electrical components. If connecting fuel pressure gauge to fuel system without using a "T" connector, DO NOT
operate fuel pump for more than a few seconds. Operating fuel pump for longer than a few seconds under this condition damages fuel pump.
- Disconnect fuel pump connector. Crank engine for at least 5 seconds. If engine starts, let it run until it stops. Disconnect fuel hose at pressure regulator and install fuel pressure gauge using "T" fitting.
- Start engine and check fuel pressure at idle. See the REGULATED FUEL PRESSURE table. Ensure fuel pressure increases as engine RPM increases.
REGULATED FUEL PRESSURE
| Application | Pressure: psi (kg/cm2 ) | |
|---|---|---|
| Legacy, XT & XT6 | 26-30 (1.8-2.1) | |
| Loyale | ||
| 1.8L PFI | 26-30 (1.8-2.1) | |
| 1.8L TBI | 20-24 (1.4-1.7) | |