Head Scratching No Start

Working on an 1990 928 S4 automatic USA edition….

This car was running fine but hasn’t been drove for a while and now won’t start. Car cranks fine, spark plugs spark, but there is no signal to activate the fuel pump relay and no pulse to fire fuel injectors. If I make the fuel pump run it will start and rev high and die.

I have pulled the CPS and it ‘test’ fine but I am still suspecting.

Any help of what else to check?

This sounds like the LH Fuel Injection module has failed, a custom hybrid circuit fails.  This is a fairly common problem with the 1987 and newer cars.