My 1988 244 wagon has been sitting for a few years because I ran out of time to work on a fuel and computer glitch. Now I am working on the problem again and to eliminate the possibility of a bad fuel pump/relay/engine sensor, I rigged a manual switch across terminals 87/1 and 87/2 of the Fuel Pump Relay. In other words, bypassing the relay coils and sending +12v directly to the Fuel Control Unit.

This does indeed put 12v at the terminals of the main fuel pump, but the pump does not make any noise or vibration to the touch. Does this indicate a bad pump, or do these pumps run silent?

Also, the car is stranded with its nose uphill on a 5% grade. If the in-tank pump is also inoperative, would the main pump deliver enough fuel to the injectors to run the engine? As it is, I don't even get a cough out of the engine when it turns over, even using the manual FPR by-pass switch.