99 bonneville, 3.8, fuel pump wiring circuit, dies on startup
 

Hi,

Eng starts and dies, pump works on start up. Removed relay, jumped pump supply and feed relay recepticals, eng starts and runs well, assumed the after start, eng runnig "takeover" system was faulty. Checked a 1998 wiring diagram (a Mistake?) it shows a oil pressure sensor taking over and bypassing relay when engine is running.

I don't usually throw parts at a problem, but in a hurry, I replaced the sensor without electrically checking the wiring and connection to the sensor. Ran for 10 min and died. I thought, in handling the wires and connections I may have temporarrily "fixed" a connection and it than vibrated loose again. Cursed myself for not thourghly checking the whole system.

But now I have partial 1999 electrical diagram and it DOES NOT show a pressure sensor baypass on running. Does the 1999 use a crank sensor signal to the ECM to keep the relay engaged after start-up. Have I been barking up the wrong tree?

I appreciate any advice
Peter

I chased something like this about 9 months ago! The pump would work for awhile then stop or bind! The only way I could find it was a fuel pressure tester, but better yet I wired my fuel pump directly to the battery, in that circut I placed a inline amp meter , when the eng began to die I could see the amps climbing on the amp meter, over 15 amps. The bearings had to be wore out, replace pump , been good sence!