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Crank No Start W/O Starter Fluid

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Old 05-15-2018, 03:19 PM
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Jon S
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Default Crank No Start W/O Starter Fluid

I am having a starting problem with my 2004 mustang GT. It will only start with starter fluid and then will run forever however if I do not use starter fluid it just cranks and cranks and cranks. In the run position I do not hear the fuel pump priming but strangely enough once I start it with starting fluid ithe fuel pump must be running because it runs for over 10 minutes.

i replaced the Fuel Rail Pressure Sensor thinking this was turning the fuel pump off at initial start but that didn't help. No codes are being thrown.

I've done the disconnect battery for days, etc. Nothing seems to work. I have 12 volts at the trunk crash switch and even bypassed it.

Any thoughts???
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Old 05-15-2018, 04:01 PM
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Urambo Tauro
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Do you still have 12V at the inertia switch while the engine is cranking?
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Old 05-15-2018, 04:07 PM
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Jon S
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Don't know. I don't have a helper. Why would 12 volt not be constant?

my problem seemed to start with a PATS System problem where my THEFT light stayed on during cranking and as I understand it PATS cuts the fuel pump off. I believe I fixed the PATS System as the theft light goes out within 3 seconds of ignition on and the car does start with starting fluid. Something is preventing the fuel pump from priming in the ON position.

Since it will ill run for 10 minutes plus once starter fluid started, I'm thinking the fuel pump is OK

Last edited by Jon S; 05-15-2018 at 04:17 PM.
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Old 05-15-2018, 04:58 PM
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Urambo Tauro
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I don't know much about PATS, so someone else will have to chime in on that.

But FWIW, that starter draws a lot of power, causing voltage to drop while cranking. IF it drops too low, things like the PCM might not stay "awake", and you can lose power to the fuel pump, too. I don't recall what the threshold voltage is, but I want to say it's somewhere in the 10-11V range. A weak or depleted battery can cause all sorts of issues, so you want to make sure that you have a healthy and charged battery.
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Old 05-15-2018, 05:02 PM
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Jon S
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Battery is new and very strong. This is so frustrating!

the car starts right up with starting fluid and will run for 10 minutes plus. So I know the fuel pump is working. The problem is the pump does not prime when the ignition is turned to ON. There is power at the inertia switch with ignition on.

Last edited by Jon S; 05-15-2018 at 06:55 PM.
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