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Fuel Pressure drops after i drive then Restart

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Old 05-04-13, 05:50 PM
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Lightbulb Fuel Pressure drops after i drive then Restart

ok i can start the car right up, drive it around and all that (38-40psi fuel presure) but then i can shut it off.Restart it and the car bogs low rpms , So i see the fuel pressure its around 30-20 psi normaly its 38-40. anyone have a idea what could cause it. I just installed a new fuel pump not it. Figured the pump was gettin heated up.
Old 05-04-13, 06:58 PM
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Can't quite understand what you're saying.
Old 05-04-13, 08:34 PM
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when i start the car up the fuel pressur is around 38-40. seems after i shut it off then restart it it only goes to 30-20 psi the lowest in fuel pressure.
Old 05-05-13, 09:37 PM
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Sounds like a sticking injector when it gets hot. (Happens in common rail diesels unsure about these injectors.)

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Old 05-06-13, 12:10 PM
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How are you measuring the fuel pressure do you have an aftermarket Adjustable fuel pressure regulator?
Old 05-06-13, 07:55 PM
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yes aeromotive fuel pressure gauge.
Old 05-07-13, 12:12 PM
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check the voltage at the pump when the pressure is low, if the voltage is above 10v and it's still low then check the fuel filter, if the filter is unobstructed then you probably either have a bad fuel pump or another issue with the fuel system(cracked hose or kinked line).
Old 05-08-13, 02:40 PM
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Where your tank vent line goes into your charcoal canister, open the opening up in the canister with a drill bit. Just clear it out, no need to take the nipple off. I think I used something like a 1/8" bit.

I had similar issue, this fixed it.
Old 05-10-13, 07:43 AM
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took that out .. changed fuel pump and fuel filter .. same issue
Old 05-10-13, 09:15 AM
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check the voltage when the problem occurs, as mentioned. it could be a bad ground or other wiring issue. heat increases resistance and vise versa
Old 05-11-13, 10:39 AM
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voltage is 13.5 or so when its losing fuel pressure.
Old 05-11-13, 10:53 AM
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were you measuring across both the power and ground pins at the pump? or just placing the + lead at the power pin and - lead at chassis ground?
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