car dies on the highway.....

Fuel Pressure Value!

Fo_Mo_Co said:

the check engine light came up, and of course went to check it at autozone and advance auto, and like most times the codes said that it was all of my o2 sensors..all four.

this is what the car does.
when im driving, and the engine reaches normal temp and after like 30 minutes of driving, the car starts to die on me. especially on the highway. i may be going 70 mph, and then the car starts to lose power and like if its needing fuel. pressing the gas pedal just makes the car shake, and stall, and eventually die.

After the engine had been running for a while, i tested the fuel pressure when the car was on, , the reading was 35-40 psi...but within five minutes of the car idling it starts going down to zero...and the car dies.

it has a new fuel filter. so wanna know if its the pump, the cps sensor, or the 02 sensors. its a 00 mustang.
any advice?????

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If your fuel pressure drops to zero while the engine is idling, you have a fuel problem. Your fuel pressure is only suppose to drop after you turn off your engine. After you turn off your engine, your fuel pressure must not drop more than 5 psi of what ever value it was when the engine was idling, for one minute. Say your fuel pressure was reading 40 psi at idle, then you turn off your engine, your fuel pressure must not drop down below 35 psi in one minute. If it does, you have a leak somewhere. But you said that while idling your fuel pressure drops to zero. It sounds like you may have a combination of fuel related problems. One being your fuel pump, sounds like it cannot keep up with your driving conditions, and secondly, you are losing fuel pressure at idle, which could mean a leak with your fuel pressure regulator, fuel pressure sensor or fuel injectors. This is just my opinion. Hope this helps. Good luck, Tommy.