fuel issues

hi guys and girls right backs better so been out to mend the old girl (v8 3.9 k plate) as she suddenly stopped working when driving made and replaced loom from fuel pump to fuel pump relay as it had no continuity replaced relays turn ignition on no power at pump , pump works cos if I take a direct feed from batt pump runs but rangie wont fire so I bridged from 87 to 86 of the relay it fired and ran yippee so turned it of had coffee but it wont fire again when tried any ideas as I fresh out cheers all

Assuming a 3.9 is the same (?) on my 3.5 EFI the pump will only run when the engine is cranking, not just when the ignition is turned on.

Ok engines cranks very strongly can hear pump if I bridge relay but wont fire

My 3.9 Classic had an issue with the fuel pump.. the PO wired a switch in (having replaced the pump to try and resolve problem) i wanted to revert back to all OEM wiring so stripped out the direct wiring and did some trouble shooting...

... what transpired is that the fuel pump relay under the seat (drivers) is working, however, the output from the ECU is feeble and intermittent, so the relay is not getting the signal from the ecu when energized. the short term fix ( i need to send the ECU for rebuild ) i used was to remove the fuel pump relay and jumper the connections, the fuel pump is permanently on when the engine is running (the impact cut out works) so like you it is jumpered for the time being with no starting issues...

with the jumpered relay when you turn the ign to 1 are you getting the fuel pump running ?

Cheers matey will remove relay tomorrow and put jumper in new ecu after crimbo then

When my 93 classic didnt start traced it to the ignition amp.

The ecu get the engine running signal from the LT side of the coil. As it wasnt firing the ecu didnt pull in the relay to introduce fuel!!

Just another thing to check!

Replaced all connectors on coil will trace wires make sure no brakes in cheers