2005 ford E350 p0191 fixed

2005 ford E350 6.8 setting code p0191 fuel pressure sensor range. Fuel pressure at idle is 65psi. Under hard acceleration pressure drops down into the low 40s, once dropped down to 37psi. So the question is, fuel pressure shouldn't drop that low should it? Plan to check the power and ground going to the pump tomorrow. Just want to make sure I'm right that the pressure shouldn't drop, atleast not that low anyway

Hey bruce, sounds like you're on the right track with a fuel pump to me. It it's available to you, try graphing the FRP and FRP_DSD (desired) and see if they agree under a load. This confirms that the PCM is commanding fuel pressure, and isn't getting it.

If it helps, here's some scan data captures I took off an '07 E-350 with the same 6.8L. Dunno what happened with ScanShare, but bump the decimal point on the fuel pressure PIDs one spot to the left.

www.scanshare.io/share/-82L7m209kyxGFOz5...1,2,3,4,5,6,7,8,9,10

Thanks. Looks like yours didn't drop below 61 psi under load and the desired stayed the same.

I didn't see desired pressure on the pid list. I'll check again tomorrow

bruce.oliver wrote: Thanks. Looks like yours didn't drop below 61 psi under load and the desired stayed the same.

I didn't see desired pressure on the pid list. I'll check again tomorrow

Sorry I didn't have any heavy load or WOT data - this was a municipal bus, so they tend to frown on speeding. :lol: But I'd be very surprised to see the desired go lower than 65 PSI during heavy loads.

Let us know what you find!

No desired fuel pressure PID on any of our scantools. But under WOT the voltage going to the pump goes up but the pressure drops. They put other cars ahead of it today. Hopefully put a pump in it tomorrow

Pulled the pump today. Tank full of rust. So now waiting on a tank. And of course it's a custom tank. The van is 4x4, converted by Quigley 4x4. They cut a few inches off the front of the tank to clear the transfer case

Ok. So when I drove it on Monday voltage to the pump was 12 volts and when I accelerated hard the voltage would go over 13 but the pressure would drop.

Got the "new" tank today. Apparently they get used tanks to modify then charge $600 for it. Anyway at idle the voltage is now 7.6 volts instead of 12 volts. Driving it the voltage goes up and the pressure stays up

bruce.oliver wrote: Ok. So when I drove it on Monday voltage to the pump was 12 volts and when I accelerated hard the voltage would go over 13 but the pressure would drop.

Got the "new" tank today. Apparently they get used tanks to modify then charge $600 for it. Anyway at idle the voltage is now 7.6 volts instead of 12 volts. Driving it the voltage goes up and the pressure stays up

Nice fix, sir! I think it's probably safe to say this engine always wants 65 PSI, then?

Yes I think so. Even though this one didn't have a desired pressure PID.