Fuel system problems
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Joined: Oct 2005
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From: Louisville, Kentucky
I don't recall a rest pressure or fuel system hold pressure being provided. KOEO means key on, engine off. What BURNSTOUGHFORD is looking for is the specification for the fuel system pressure with the key off. There is no specification for this in the service manual that I am looking in. 
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KRM02,
I'm sorry you "don't recall" or find the "specification" in the manual you're "looking in". I both clearly recall the test for rest pressure & have seen it in manuals I've looked in.
As I posted, you must run the motor 1st in order to establish normal fuel pressure in order to conduct this test. "KOEO" does not neccessarily mean do not run before you test. Either way, key on or key off, the idea is to pressurize the system & monitor how long the pressure holds. Leaving key on w/motor off will not keep the fuel pump running, its turned off by PCM momentarily anyway. You can not see pressure drop off if pressure isn't 1st generated.
If there's no check valve(s) or test for them holding pressure, as you suggest, BURNSTOUGHFORD's Q would be moot. I presume the manual you're "looking in" cautions about gas spraying out & instructs you how to relieve the pressure at rest before a fuel line is disconnected? Many will hold pressure for hours. Those that leak down quickly may take a bit longer to start, a hot motor may push vapor all the way back to the tank.
I'm sorry you "don't recall" or find the "specification" in the manual you're "looking in". I both clearly recall the test for rest pressure & have seen it in manuals I've looked in.
As I posted, you must run the motor 1st in order to establish normal fuel pressure in order to conduct this test. "KOEO" does not neccessarily mean do not run before you test. Either way, key on or key off, the idea is to pressurize the system & monitor how long the pressure holds. Leaving key on w/motor off will not keep the fuel pump running, its turned off by PCM momentarily anyway. You can not see pressure drop off if pressure isn't 1st generated.
If there's no check valve(s) or test for them holding pressure, as you suggest, BURNSTOUGHFORD's Q would be moot. I presume the manual you're "looking in" cautions about gas spraying out & instructs you how to relieve the pressure at rest before a fuel line is disconnected? Many will hold pressure for hours. Those that leak down quickly may take a bit longer to start, a hot motor may push vapor all the way back to the tank.
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