under pressure
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Freshman User
Joined: Nov 2003
Posts: 40
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From: evansville,in
under pressure
hooked up pressure gauge to 302 efi 1986 van and it went 40 pounds momentarily then dropped to zero...key on not running...tried test several times always same...started van and it reads 38 lbs and holds fine..what causes the key on leakdown?
Hotshot
Joined: Aug 2002
Posts: 12,679
Likes: 15
From: BC, Canada
It sounds like you probably need a new fuel pump. The fuel pump has a check valve in it.
The supply check valve, which is normally closed, opens when the outlet pressure from the energized fuel pump exceeds the opposing check valve spring force. When the fuel pump is de-energized (i.e., engine is shut off), the supply check valve closes to maintain fuel pump prime and fuel supply tube pressure.
The supply check valve, which is normally closed, opens when the outlet pressure from the energized fuel pump exceeds the opposing check valve spring force. When the fuel pump is de-energized (i.e., engine is shut off), the supply check valve closes to maintain fuel pump prime and fuel supply tube pressure.
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