fuel pressur spec

[jerry stanton]

need fuel pressure spec on 1988 Isuzu Trooper II with 2.6L 4 cylinder engine. Runs poorly, and has 15-16 PSI.

[Strugari]

It is a little bit of a procedure.

1. Install the gauge between pressure regulator and distributor pipe. Unplug the VSV (Vacuum Switching Valve) Start engine and measure pressure under all of the following conditions.

Disconnect pressure regulator vacuum hose. Plug intake side of the hose. Pressure shoulg be 42.6 (3.0 kg/cm2.

Reconnect pressure regulator vacuum hose and allow to idle. Pressure should be about 35.6 (2.5 kg/cm2)

Shut off engine. Disconnect vacuum hose from pressure regulator. Pressure should be 35.6 (2.5 kg/cm2)

Apply batter voltage to the VSV, reconnect vacuum hose, and allow engine to idle at 900 rpm. Fuel pump pressure should be 42.6 (3.0 kg/cm2). If the pressure remains unchanged, replace the VSV.

Hope this helps!

[jerry stanton]

Hey, thanx for the info. Yep it was a worn out pump. New pump installed "pegged" my 35 lb gauge, and now the old Troop runs like new again! Thanx again for the specs.

[Strugari]

No Problem,
Glad to help where I can