91 80 quattro with fuel pump problems. pump runs when jumpered, fuse good, fuel pump relay not marked and do not know location. car runs good with pump jumpered. can someone help in troubleshooting pump problem?

so you saying when you jump the relay it works or what?

i have a 84 5000 turbo with a simalar problem my relay has to be switched manuly ( stick a piece of paper to make contact for the switch) so my guese is there theres no power going to my switch. i do not know the cause of this my self but have been tryen to figure it out. it may be the ignition switch ( well i think so ) my audi allso over heats realy fast and consiqently loses power and seems like the engine isent geting any gas. this some how drains my batery( but my batery still hase 12 volts) not sure how to mesure cold crank amps but engine wont respon to the turning of the key not even a lil turn over. i dont think its the starter though, but at this point thats just wishfull thinking. not sure if ur having any of these problems also but let me know i need as much help as i can get. i think we could help one anouther.

fuel pump relay should be located below the windshield behind the fire wall numbered 10 at least it is on the UK cars

if the car runs with the power diverted direct to the fuel pump you can bet the relay is down