Fuel Pump/Relay Problems

[Civic EGK]

Hey guys,

Just bought a new Walbro Fuel Pump the other day. Pluged it up and tried starting the car and it didnt start, the fuel relay was making clicking nosies so i pluged the old one back in but it did the samething. so i checked all the fuses and bought a new relay but still no luck.. also check all the wiring from the pump to relay and relay to ecu.

what could be the problem..?

[ECU-MAN]

what ecu are you runnig ?

[ECU-MAN]

are you running a convertion harness ?

[Civic EGK]

no i rewired it, but im pretty sure its all right. it was running fine before i changed the pump over..

[ECU-MAN]

sounds like a broken wire, or bad earth on the thermostat housing

[qikteg]

when you say "also check all the wiring from the pump to relay and relay to ecu.", have you:
1. tested the main relay?
2. tested the main relay plug, and its wiring to the 12v/ignition?
3. done it as per the factory service manual/haynes manual test?

if that passes all those diagnostics, Next i would check to see if the pump is getting 12v at ignition. get someone to crank whilst you're testing the plug at the fuel pump end. if you are getting 12v, i'd test the pump directly off 12v to ensure that the pump is actually working.

my problem was a wiring issue, with a short to ground that kept blowing a fuse. recheck all your fuses individually. once a fuse is blown, most diagnostics are useless.

[jdm_b16a]

The pump will have power (+12V) and EARTH. The power is picked up from the relay. If you wired the relay correctly you should hear a 'whirr' as the power spins up. No 'whirr' then the pump is not getting power.

Test the pump (momentarily - don't extend) use a small battery and connect +ve to +ve and EARTH to EARTH. If pump 'whirrs' its OK.

Check the relay with the pump again. No 'whirr', try another relay. Still no 'whirr' then check power source. If your relay is wired correctly the pump should fire up.

Just out of curiousity, are you using the correct relay? Have you checked the FSM wiring diagrams for correct connections?

Peter

[Civic EGK]

i think i found out the problem, i don't have any voltage going through the STS wire to the relay, but i did a continuity test from the fuse to relay and ecu to relay and its fine. i dont know what else to try.

[CRXer]

STS is the start signal.
voltage only applied when u turn the ign key to start,ie crank.
do a continuity test between the start terminal on the ign key switch & the start pin at the main relay with the start fuse plugged in.

[ECU-MAN]

if the STS is at faut, you should be able to push start the car.

[Civic EGK]

Ok thanks guys I'll give it a try

[Civic EGK]

i did a continuity test between the start terminal on the ign key switch & the start pin at the main relay with the start fuse and there is still no voltage going through, so i pushed started the car and it started. so does that mean the ecu is stuffed?

[CRXer]

your not testing for voltage on a continuity test,your testing for a wire that is continuous,ie unbroken/low resistance,

u have to find out where the break is to stop your main relay & ecu seeing the start 12V signal.

unplug the small wire off the starter motor & hold the key on the start position & see if 12V shows up on both sides of the start fuse with the fuse in place.
then test u have unbroken connections from the ign switch start terminal to the main relay & ecu with a continuity test or see if 12 V shows up at the main relay & ecu when holding the key on start