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Car drove fine the previous day. Today it would crank but not start. First thought was that the fuel pump gave out, as everything else seemed fine, and I did not hear the fuel pump priming when the ignition was turned on.

  • So, are you saying you bypassed your Fuel Pump Inertia Shutoff Switch? – Glen Yates Oct 16 '17 at 18:50
  • @GlenYates No, didn't bypass the Inertia Shutoff Switch. Inertia switch is wired to relay power. I tapped into pump power after the relay. – Montana Harkin Oct 16 '17 at 21:21
  • @CharlieRB Thx, updated to be more Q/A – Montana Harkin Oct 16 '17 at 21:21
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This is to recap the work I did to troubleshoot and diagnose my Kia not starting due to no fuel pump. Hopefully will help others with a similar problem.

Diagnosis

I checked the pump fuse and pump relay to ensure they were fine. No issues.

After sourcing and replacing the fuel pump, it still did not turn on. Damn, wasn't the pump.
(2 hours to extract the pump module, replace the pump, and insert the pump module)

Diagnosis #2

Now to test the actual wiring to the pump. Re-checked the relay. Re-checked the fuse. Still fine.
Tested continuity between power output from pump relay to pump. No continuity.
There's the real problem.

After trying to identify where the break was, and realizing that the wiring for the pump ran through the cabin and the center console, I opted to run new power to the fuel pump from the fuse block.
Tested running new power to pump from relay. Car started right up.

Ran wire from fuel pump, along bottom of car alongside brake lines, up to engine bay. Identified the power wire for the fuel pump by:

  1. Finding the pump power output pin from the relay.
  2. Test for continuity to the output side of the fuse block.
  3. Verify pin is correct by checking wire color on pump, hey they matched.

Soldered wire to the pin on the fuse block. Soldered wire to pump.
3 hours to diagnose and run wire.

  • 1
    You could of saved a lot of time by checking this from the relay. For future reference terminal 30 is an always hot power source, 87 is the path to the pump, 85 and 86 are relay coil power and grounds. With the relay removed terminal 87 should be grounded. If it's not the pump or in your case the wiring is bad. – Ben Oct 16 '17 at 21:38
  • Yup. My bad for not checking the wiring first. Never would have thought it would go bad so quickly in a 12yr old car. – Montana Harkin Oct 16 '17 at 22:18

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