1994 850 Stalling and Problem Restarting diagnostic code 131

Desparado · Post by **Desparado** » 24 Jun 2007, 20:17

In the service manual, it reads the main system relay is energized by the fuel system ECU and provides power for the fuel pump, the relay remains energized only as long as the ECU recieves an RPM signal from the ingnition system ECU. No signal or lost signal due to a faulty Crank position/RPM sensor the relay will de-energize and the fuel pump will stop operating Hense stalling and hard to start. Hanes Repair Manual 97050 chapter 4 page 6 paragraph 9 System Relay.

I am replacing the Crank position/RPM sensor this week and will let you know if it fixes it.

Post by **Ozark Lee** » 25 Jun 2007, 07:49

Before you replace it, make sure the wires from the sensor are routed well clear of the coil wire. Use a ty-wrap to make sure it stays clear.

...Lee

flaco · Post by **flaco** » 25 Jun 2007, 09:53

on the 940 engines, the pump relay output on the ecu would often die, so I just soldered inside the ecu to have an always-active fuel pump, as long as the ign switch was in the on position.

some may argue about safety here, but compare that to getting a new ecu from the stealership... (pre-ebay days)