Fuel Pump Relay (Impulse Turbo)

ECM powers relay as long as ECM receives ignition reference signals or starter crank signal. Relay should be tested in same way other relays are tested. See Fig 1 .

Fig 1: Fuel Pump Relay Schematic (Impulse Turbo)

Courtesy of ISUZU MOTOR CO.

FUEL PUMP PERFORMANCE

Application

Unregulated Pressure psi (kg/cm² )

Regulated Pressure psi (kg/cm² )

Impulse

Non-Turbo

⁽¹⁾ 35-38 (2.5-2.7)

⁽²⁾ 25-30 (1.7-2.1)

Turbo

⁽¹⁾ 39-47

⁽²⁾ Slight Drop

Stylus

35-38 (2.5-2.7)

25-30 (1.7-2.1)

⁽¹⁾	With ignition on and vacuum hose disconnected from pressure regulator.

⁽²⁾	With engine at idle or with 12-14 Hg. vacuum manually applied to pressure regulator.