1987 audi 5000cs intermintent start Fuel pump

[urq]

The ECU turns on the fuel pump after it checks the inputs for validity, so
your loss of fuel pump is more likely to be a symptom than a cause.  That
said, I have seen times where the car has been sitting for a while and the
lack of fuel pressure prevents the ECU from powering it up.  I never tried
to figure out what caused this, I found that pressurizing the system by
manually closing the FP Relay primed the system and then the car started.  

I'd recommend that you check the ECU input signals like the speed and
reference sender on the flywheel and the Hall sender on the distributor,
then the coolant temp sensor.  If the engine isn't starting you'll get a
speed sensor code, but you may want to read codes from the ECU when it is
having a difficult time starting.  

Steve Buchholz

-----Original Message-----

hello i have a 1987 5000cs. my problem is that i am not getting power to my
fuel pump all the time. for instance it will take two to four times of on
off start before i can here my fuel pump run. when this problem first
started we did not have spark either. but i am assuming that is because of
the pump not being powered. i have ran every single electrical test in the
book and everything checks out. i also swapped distributers,crank case
sensors, ecu's and many many other things including the ignition switch. i
do have a bosch 044 fuel pump and a fuel cell in the trunk. baiscally my
question is does anyone know what controls the power sent to the fuel pump.
the original wiring for the original pump now goes to the inline Bosch pump.
i have been stumped for weeks and have found nothing. please help