hi have an 07 taurus that wont stay running and has trouble starting. A scanner shows the fuel pressure at 73 constantly does maybe go up to 73.3 with key on. Even with the lower fuel line disconnected it still shows 73. IS there a chance the sensor could go bad or is there something else?

FIXEDHAD ALT AND FRPS PLUGS BACKWARDS CAUSING FP TO READ MAX,

 

Have you checked your spark plugs recently? It sounds like one of them may be bad.

 

SEL, is that the only thing that showed up with the scanner?
Honestly, I don't know what the proper fuel pressure range for your car is. But it is possible that a sensor malfunctions. I would use a fuel pressure gauge to see what happens and if it shows different values than the scanner the sensor may be the cause.

Go-part: you shouldn't be writing, you should be reading.

 

http://img849.imageshack.us/img849/8494/capturehfw.png
^ Im sorry, but i checked here and this was one of the suggestions.. Im only trying to help.

Ok, i just checked some specs on your car and it tells me that your fuel pressure should be at 30-55psi when the key is in and the engine is off and 26-45 when the engine is running

 

Ok I just talked to a ford tech and we came up with these steps for us to better help you determine what is wrong with your car

"crank no start can be several things. Getting no fuel is the most common thing. You need to verify that there is spark and fuel. Unhook a plug wire and with someone cranking the engine see if the plug wire will arc to the block. If there is next check is real easy. Go with a can of starting fluid or carb cleaner and spray down the intake while someone is cranking. If it starts up off of the fluid you're spraying you have a fuel issue.

third issue I come across is air. Possibly a bad IACV allowing to much airflow or an egr valve stuck open. Easy way to test for that but not always effective is try starting the car with part throttle. If you can manage to start the car with part throttle and keep it running by goosing the throttle you likely have an issue with either the egr system or iacv."

 

theres no schrader valve so i cant physically test pressure but i guess only thing to go by is what pcm shows? is that suppose to be current psi at the rail?if so it never really changes. I can "prime" the car with a few key cycles and itll start half *** for a few seconds before dying out. I guess i could try rigging some kinda gauge to fit off filter but pooey

i think its the later one with pressure sensor on rail but ill check up on that

 

Before you get involved trying to get all kinds of pressure readings , it might be a good idea to get hold of a manual for your vehicle. The newer ones have returnless fuel systems where the pressure regulator is in the tank. On top of that , the newer ones use a pulse width modulated signal dependent on the pressure sensor on the fuel rail that controls a fuel pump driver module located at the rear of the vehicle.
Hopefully the correct manual will help sort this out for you and possibly clarify a lot of what is going on.
I forgot to mention all this is also monitored by the PCM.

 

well still havent figured this thing out. Replaced fuel pump and does run a little longer but stalls after min or two. Also tried couple junkyard frp sensors and no change unless they just all went bad. Still havent been able to verify fuel pressure as ive yet to find the inline adapter. GOing to check the egr iac, etc make sure they arent hanging open. any grounds that could cause an issue? The car had blown headgaskets but have been replaced just trying make sure something wasnt left disconnected. Both sides of the fprs read 12 volt but dont really know what that means as ive yet to find detailed schematics or manuals

 

I'm trying to keep up with you, could you please tell me what you mean with fprs?
You may be on the right track with a different approach.
Are you getting a check engine lite?
Is this problem just showing itself after completing the head gasket work or has it run a while since the work was done?

 

frps fuel rail pressure sensor car has been tossing p0191 high pressure or w/e. Finally got a gauge on it and pressure drops to 10psi once started. So it seems like itll prime but once started wont keep power to the pump or something just isnt signaling it to come on. Car was bought at auction so really dont have any details or background other then look like someone tried to kill it. Had to replace gaskets, heads (cracked seats) and rings before it would run at all. Cleaned the tank before firing and recently bought new fuel pump just incase that was problem. Any fuses, resets or check valve in the tank could be bad? Seems like it maybe in a default or safety mode. From what i understand the frps is what powers the pump when pressure drops too low so if its stuck ready high 73psi then the pump just wont get power. Maybe both sensors i had tried were just bad or could there be ground, short somewhere?

What does the vac line going to frps do?