Do you have a test light or voltmeter? You Can do some power tests at the pump relay. But first, hold your finger lightly on the relay while someone cycles the key from off to ON. You should feel the relay click every time key goes from off to on. This means the control side of relay is working, both the signal from pcm and the ground for that control side. If the relay doesn't respond, the signal from the pcm may be lost or the ground side of relay control is lost.
Pull the relay out, ground your test light to battery negative, and probe all the slots the relay plugs into. With key off, one should be hot -the power feed for the pump. This will be terminal #87 on the diagram on side of relay. Take a jumper wire from that #87 slot and go to #30 slot (look at the sketch on side of relay. Be careful not to put jumper wire into wrong slot-that would be very bad, could fry your VCM. Jump from power feed #87 to #30. That sends power directly to the fuel pump.
If you follow, by now you may have found why pump won't come on.
Did you feel relay click? If not, use test light grounded to negative battery, and probe the other two slots where relay plugs in-this will be in diagram, #85 and #86. (#87A is for testing pump prime-don't worry about that slot now.) Hold tester probe in #85 slot and have helper turn key to on, not start. The signal from computer will last for 2 seconds after key is turned to on, and then signal stops. Do you have power for 2 seconds in #85 slot when key is turned to ON? Then signal from computer is good. Now check ground side of relay's control side. If you can use test light ground clip into #86 slot (maybe stick a metal paper clip into slot #86 and clip ground clip to that.)and keep tester probe in #85. Now have helper cycle key to on, If your test light lights up for 2 seconds, the control side of relay is all good.
Let me know what you find. You have just tested the relay's wiring for the fuel pump.
I would interrogate the fuel pump relay socket with a voltmeter or test light. There should be one hot terminal from the ecm b fuse. There should be a terminal that has chassis ground for the relay coil. The positive terminal for the relay coil comes from the ecm when the key is on. If you have trouble interpreting the results of these troubleshooting steps, feel free to comment back. The circuit is on the right of the diagram about 1/3 down the page.
SOURCE: fuel pump problems 2003 s10 chev 4.3 v6
Your ECU is what acctivates your fuel pump realy. Put the key on the run possition and pull the ecu fuse for a few seconds and reinstall it ans it should accivate your realy for 5 seconds, Good luck.
SOURCE: 2000 S10 4.3L
At the fuel pump relay you should have 1 full time hot wire. 1 hot wire when you turn on the switch. 1 ground, and the other wire goes to the pump. Test the ground to be sure it is good. If so then jump a hot to the one that goes to the pump and see if it runs.If it does then you have a bad relay or ECM. You can swap the relay with another of the same # from tour fuse box to test it.There is also a ground on top of the frame near the filler neck, check it too. Good Luck
SOURCE: 1999 GMC Suburban 350 wont run
Per your description, it sounds like you are missing an injector pulse from the ECM.
Check the under-hood fuse box and verify the "ECM1" fuse is good (12 volt supply to injectors).
With the key in the run position, verify you have 12 volts at an injector.
Barrow or purchase a "noid" light to verify you have an injector ground pulse from the ECM.
Let me know what you find and we can proceed from there.
Regards,
SOURCE: no power at fuel pump chev.S-10 looking for fuel pump relay and fuse
The fuel pump relay is located Under hood, driver side, upper firewall, mounted in
relay block.
The fuse is located under the instrument panel to the left of the steering column.
The fuse block should be visible from underneath the steering column,
near the pedal bracket. If the panel is not visible, check for a
removable compartment door or trim panel which may be used on later
models to hide the block.
SOURCE: 2001 chevy s 10
Find power wire coming from relay to pump when key switched on, & follow it back to pump. If you have power out of relay & nothing at pump, then I'd look for a break in wire to rear, or just run a new one. Double check your ground as well.
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