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Fuel system no pressure

6K views 100 replies 6 participants last post by  charlescrown 
#1 ·
No pressure, fuses, relays good. Changed fuel pump. Hear what I thought was usual pump sound when key is turned to on. No voltage at fuel pump check at engine bay fuse block. Could it be fuel cutoff switch next to master cylinder?
 
#2 ·
Can you check for fuel pressure?
No?? Check voltages at fuel pump relay
Two should have 12 volts
Jump pins 30 and 87. Listen for fuel pump.
If fuel pump running, try to start engine.
If it does start then relay
If it doesn't start then check fuel pump
Sometimes one forgets to transfer the O-rings to new pump.
 
#3 ·
It would be really helpful if you could tell us what model of Santa Fe we're working with since you haven't posted in one of the model specific forums. And knowing what engine the car is fitted with usually helps too when your asking for advise about an engine problem.

Could it be fuel cutoff switch next to master cylinder?
I assume your talking about an inertia switch? It couldn't be the inertia switch if there is no power at the pump check terminal on the fusebox.

Have you checked to see if there is spark at the plugs? No fuel delivery & no spark more often than not means there is a crank sensor circuit problem.
 
#15 ·
I replaced every sensor on this engine from a 2004 at pull apart. I can hear fuel pump on. There is still no pressure when I disconnect line at regulator. Bought a new regulator also. I'm wondering if the crank sensor I bought online has gone out after a couple of miles?
 
#16 ·
Who changed the fuel pump?
Have seen many times where the owner changed the fuel pump
And, a no start followed.
Usually due to O rings which were not transferred to the new fuel pump
Even though the fuel pump runs, it can not build up enough pressure for the fuel injectors to work properly.
Old carburetors used about 3 to 5 psi. The modern day fuel injectors require anywhere from 40 to 60 psi.

Note: I believe if the crank sensor was not working then the ECU would not see a crank signal
And the ECU would not run the fuel pump. Nor would there be spark nor injector signal.
 
#19 ·
I went further and there is voltage at the fuel pump plug but the fuel pump is not coming on. The sound I thought was the pump is coming from rear hatch. It stops when hatch is opened. Checked o rings, they seem good. I turn key to on and open the fuel tank cap and there is no sound. I bought 2 pumps from pull apart and have tried both in tank. Neither will pump ?
 
#30 ·
Took a known good relay from fuse block and put in fuel pump position. Pump does not work. Put that relay back in horn position and horn does work. Can I jump relay and run indefinitely if needed, knowing that I have to disconnect jumper when motor is not running until I can find wiring issue?
 
#31 ·
So we're back to post #2 again...LOL

Remove the pump relay from the fusebox.
Switch the ignition on.
Connect your black voltmeter probe to battery negative.
Touch the red probe to each of the terminals of the pump relay socket on the fusebox.
You should have two terminals with 12V, one terminal with a low voltage (usually about 2.5~3V), and one with 0V.
Let us know which one of the voltages is missing and that will tell us which part of the circuit the fault is on.
 
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