Strange fuel pressure reading... key on/engine off. Help?

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Dec 5, 2004 | 02:33 PM

Ed FvC

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Strange fuel pressure reading... key on/engine off. Help?

I've been having some issues with the car, where it's leaning out when going to WOT. After a week's worth of troubleshooting and ruling things out, it's now down to one of two things: fuel pump or injectors. The motor is stock, including all fuel systems.

Checking the fuel pressure today, and this came up... At idle, fuel pressure remained steady at 58-60psi. Trying a key on/engine off test, however, it jumped up to 55 and quickly dropped back down below 45psi.

From what I understand, this isn't right...but I have no idea why. Help?

Dec 6, 2004 | 01:09 AM

red90cobra

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From: Murphy, Tx

Yes that's bout right. You have to have the car running to keep the fuel pressure up. The pump only bumps on for 2 seconds then turns off. Mine does the same thing. Have you changed your fuel filter?

Dec 6, 2004 | 08:16 AM

Ed FvC

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I know it's supposed to drop. However, it's not supposed to drop 10 psi in less than 10 seconds, and certainly not below 45 psi.

Yes, I changed my fuel filter.