FUEL PUMP?

MIKE SKI

MEMBER
1987 SAAB 900
4 CYL
2WD
MANUAL
90,000 MILES

I have a 1987 turbo saab there is no gas in the fuel rail. The 20 amp fuse is good for the fuel pump but there is no power on either side of the fuse box for this circuit even with the key in the on position. Is there another fuse box, fuse or a relay that I may be missing to locate.

No power to fuel pump when pump is by - passed with 12 volts it works and supplies fuel to rail ----the car will crank but not start when starter fluid is injected to the intake the car run and then stops so the electrical and compression side are good seemed like the injectors are not working and no current to the fuel pump let sit over nite and car started could this be a bad crank sensor in the making. Does the crank sensor control the current to the injectors? The pump fuses are good is there a injector relay please help thanks

2 Replies

DAVE H

MECHANIC
13,383 POSTS

It does sounds like the crankshaft sensor but we should check the fuses and relays.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

FUSE PANEL RELAY ID (INSIDE MAIN FUSE PANEL)
Fig. 3: Fuse Panel Relay ID (1984-90)(Inside Main Fuse Panel)
Courtesy of SAAB-SCANIA OF AMERICA INC.
1 - Headlight Relay
2 - Headlight Relay
3 - Rear Window Demist Time Relay
4 - Ignition Amp Relay (1987-88)
5 - Ignition Lock Relay
6 - Fuel Pump/RPM Limiter Relay (1983-84 Turbo)
6 - Prewired For Foglights Option (1985-86 16-Valve Engines)

6 - Upshift Light Relay (1988 Manual Transmission)
6 - Blank (1989-90)
7 - Fuel Pump Relay (All 8-Valve Engines)
7 - Foglights Relay (1987-90 16-Valve Engines)
8 - Blank (1984)
8 - Shift Light Relay (1985-86 8-Valve Engines)
8 - A/C Relay (1987-88), Time Delay/Relay (1989-90)
9 - Cooling Fan (A/C) Relay
10 - Horn Relay

Check out the diagrams (Below). Please let us know what happens.

Cheers