fuel pressure

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Oct 7, 2012 | 03:36 PM

ollieman

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From: upstate new york

fuel pressure

what should the pressure be on a 98.5 when at idle and then under power? can you check the higher pressure by just reving engine or do you have to drive?

Oct 7, 2012 | 03:40 PM

Shovelhead

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From: Central VA

"Normal" idle (stock pump) should be around 15-18 psi.
"Normal" Wide Open Throttle WOT under load (stock pump) should be greater than 8 psi.
Aftermarket Lift Pumps will change these readings depending on whose setup you've installed.

Oct 7, 2012 | 05:17 PM

ollieman

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From: upstate new york

why is the idle psi greater than under load?

Oct 7, 2012 | 06:18 PM

SIXSLUG

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From: Pacific NW, B'ham, Kalispell MT

Because the injectors are draining away fuel faster than it gets replaced by the pump.

Oct 7, 2012 | 06:24 PM

Shovelhead

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From: Central VA

The Lift Pump is electric, not driven by the engine.
Increased RPM does not equal increased pressure/flow.

Oct 10, 2012 | 02:24 AM

peter50

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I am not quite sure but this problem could also be occur due to the radiator fault. if there is a bit leakage in radiator or it gonna empty then the fuel pressure will diffidently got up.