I haven't worked on wiring issues for a while (and have limited memory storage), but when the key is turned on the fuel pump should run for a short period (5-10 seconds) then shut off until the motor runs (I think it is rpm's).
I would look at other wiring issues before investing in new ECU. My experience is that they are more robust than advertised.
I suspect that there is a short in the wiring and they hard wired the fuse to keep things working, which may have melted some wires together. Check your other fuses and make sure they are correct size (a larger fuse than normal may be an indication of blowing normal fuse).
Ok, checked the FSM.
Fuel Pump Relay Pins
- #1 Blk/W hot all the time - relay coil pwr
- #2 Blu/Blk hotwhen key on - relay contact pwr
- #3 Pnk to ecm for grnd to relay coil - should be 0 volts for 5-10 seconds when key on, then float to battery voltage
- #4 Pnk/Blk pwr to fuel pmp - should be 12v for 5-10 seconds when key on then 0v until motor runs
Check that #2 pin is alway hot when key on. If it is cycling that means the main relay is cycling which is why the fuel pmp cycles (a break in input pwr).
Check Fuse Block 1 FI fuse 15 amp (under hood) Pwr to Main relay switch, Fuel pmp switch
Check Fuse Block 2 IG-Coil fuse 15 amp (under dash) Pwr to CEL/MIL, Main relay coil, Fuel pmp relay coil
Hope this helps. Helpful to know 5 spd., or which auto?