RedCandy10

First of all, I am new to the forum so thanks in advance for any input. I have a 2010 GT (I know I know should have waited for the Coyote). I bought the car new off the showroom floor, it now has 105k miles of completely care free problem free driving until about a month ago that is. The car started off with an issue of completely falling on it's face under hard acceleration but was so intermittent the first month that I could not troubleshoot it. But the problem has gotten worse and worse over the past month. I have changed the fuel filter, cleaned the TB and replaced the Mass air sensor, and just a week ago replaced the fuel pump with a motorcraft part from the factory. The car cleared up and ran fine for a week, but this afternoon while out joy riding, the car started bogging and went into limp mode throwing code P0191, fuel rail pressure. I guess I'm curious as to whether anyone else has experienced this issue? Found a solution? I know I have wrote a book but I figured it's easier to get it all out there in the beginning, again, thanks in advance for any input or help 👍

imp

When I got the P0191, I replaced the Fuel Rail Pressure and Temperature Sensor, and that fixed it, but it was an Explorer, not Mustang.

RedCandy10

Thanks for your input, was you experiencing similar symptoms to what I am? Loss of power and bogging down? Just curious thanks!

imp

Actually, no symptoms other than the annoying check engine light, then worry over what happens when the sensor fails completely. The Fuel Pressure and Temperature Sensor is used to control the fuel pump output to maintain constant fuel pressure. Pressure is kept constant by varying the speed of the fuel pump. So, I asked myself, if the sensor dies, does the pump stop, leaving me stranded? Ford thought of that possibility.....failed sensor tells the pump to run at full speed, the pressure then being well over normal, governed by a relief valve in the fuel tank, and causing very rich operation of the engine, smoky exhaust probably.