Introduction

UNDERSTANDING THE 750iL FUEL PUMP UPDATE


As of June 1988 production the BMW 750iL was equipped with an advanced fuel control system which provides complete fuel system shutdown during periods of failsafe (6 cylinder) running.

The fuel pump update retrofits this improved fuel control system to earlier production vehicles (9/87 thru 5/88) so that all BMW 750iL vehicles operate with the same advanced, improved design.

The update steps which follow will achieve the following:

- Installation of 2 ignition sensing fuel pump relays for fuel pumps I & II.

- Elimination of the existing fuel pump relays.

- Transfer of fuel pump power control to the new fuel pump relays.


- Transfer of fuel injector power control to the new fuel pump relays.

- Transfer of purge valve power control to the existing main relays.

- Retention of the DME/AEGS Revolution ("TR") signal.


- Access of a terminal # 50 signal for new fuel pump relay activation during cranking.

- Installation of an additional wiring harness to complete the update wiring changes.


Please proceed to page 1, Preparatory Instructions.