fuel problems

1985 MERCURY MARQUIS
185,000 MILES • 5.0L • V8 • 2WD • AUTOMATIC
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DALE JOHNSON2
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The vehicle starts but will not stay running. have changed, fuel pump, fuel filter, pump relay, ignition switch, catalytic converter, distributor, oil level is fine. the motor does not use any oil. Only have 9.2 volt to fuel pump in the on position. I am scratching my head.
Oct 17, 2017 at 8:23 AM
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MHPAUTOS
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Do you have fuel pressure when the engine stops? are you able to test for this?
Oct 17, 2017 at 11:30 PM
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DALE JOHNSON2
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No on the fuel pump pressure. Only have pressure in the start position. The engine use to run until it warmed up and then stop, now it stops as soon as you release the key.
Oct 18, 2017 at 6:15 AM
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DALE JOHNSON2
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Have also replaced the O2 sensor and coil.
Oct 19, 2017 at 7:03 AM
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DALE JOHNSON2
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Also changed the ignition module.
Oct 19, 2017 at 4:53 PM
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STRAILER
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Can you shoot a quick video of what it is doing so we can better see? Upload it here at your reply.

Cheers, Ken
Oct 20, 2017 at 2:15 PM
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DALE JOHNSON2
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I've had to get 12v from a different source as the 9.2v from the relay was not sufficient to run the fuel pump.in the run position on the ignition switch. works fine now, why the low voltage I don't Know, It does not appear to be a wiring problem. any suggestions?????? Thankyou.
Oct 21, 2017 at 7:42 AM
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STRAILER
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We need to find where the voltage drop is happening. Here is a guide and fuel pump wiring diagram so you can do some testing.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Please let us know what happens.

Cheers, Ken
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Oct 21, 2017 at 10:42 AM