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Old 07-06-2015, 04:39 PM   #1
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will faulty crank sensor shut off fuel pump?

hi all,

removed whole exhaust tonight to fit new gaskets, clamps and brackets.

while exhaust was off i started it and revved it a few times, it then died.

fuel pump not running,

fuse, relay and pump ok,

am i right in saying the crank sensor can shut down the fuel pump?

anythink else that can shut it down?

car cranks fine with no untoward noises, i figured the noise created by revving it with no exhaust on has killed something,


thanks
barks

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Old 07-06-2015, 04:46 PM   #2
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Yes..........................
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Old 07-06-2015, 05:00 PM   #3
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thankyou :-)

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Old 07-06-2015, 07:37 PM   #4
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When the CPS fails, I think the ECU 'thinks' the engine is not rotating. Therefore there is no need for any fuel.Therefore the fuel pump relay gets no signal.
CPS is not very expensive. About $90 in USA. The part number for mine(but verify for yours) is:
BOSCH - 0261210204
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Old 10-30-2015, 05:49 AM   #5
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Originally Posted by Gelbster View Post
When the CPS fails, I think the ECU 'thinks' the engine is not rotating. Therefore there is no need for any fuel.Therefore the fuel pump relay gets no signal.
CPS is not very expensive. About $90 in USA. The part number for mine(but verify for yours) is:
BOSCH - 0261210204
But doesn't the fuel pump run when you put the key in the on position (not the position to start the car) ?
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Old 10-30-2015, 06:08 AM   #6
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But doesn't the fuel pump run when you put the key in the on position (not the position to start the car) ?
Yes, but only if the static fuel pressure is low; otherwise it does not run which is why you have to pull the relay and jumper the system to make it run on purpose for testing.
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Old 10-30-2015, 06:31 AM   #7
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so I checked fuel pressure at rail by depressing shrader valve and got nothing. Then I put ignition to on and checked the fuel rail again and still nothing. You're saying it can still be the CPS and the only way to tell is to jumper the system and see if getting pressure by fuel rail?
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Old 10-30-2015, 06:36 AM   #8
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so I checked fuel pressure at rail by depressing shrader valve and got nothing. Then I put ignition to on and checked the fuel rail again and still nothing. You're saying it can still be the CPS and the only way to tell is to jumper the system and see if getting pressure by fuel rail?
Possible, but if you pull the fuel pump relay and jumper the pump (do a search for procedures) and still get no pressure, you have a pump issue as this bypasses the CPS.
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Old 10-30-2015, 07:32 AM   #9
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so I checked fuel pressure at rail by depressing shrader valve and got nothing. Then I put ignition to on and checked the fuel rail again and still nothing. You're saying it can still be the CPS and the only way to tell is to jumper the system and see if getting pressure by fuel rail?
The valve can be awkward to operate.It is an unusual size.
If there is zero residual pressure in the system & the pump does not run with key "on" Then the fuel pump electrical system is suspect. Easy to test.
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Old 11-02-2015, 06:29 AM   #10
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Possible, but if you pull the fuel pump relay and jumper the pump (do a search for procedures) and still get no pressure, you have a pump issue as this bypasses the CPS.
Is this definite? I jumpered the pump and there was still no fuel pressure. I hooked up a test light to the #30 slot and there was power so I assume power is going to the pump and it is not working. Am I correct and does that mean it is definitely the pump?

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