5.4l will not rev over 3k rpm
Asked by leswall Mar 28, 2016 at 04:06 PM about the 2005 Lincoln Navigator Luxury RWD
Question type: Maintenance & Repair
Throwing code p0191 for fuel pressure sensor.
Runs great till 2,500-3k rpm then spit, sputter.
Down shift for more rpm and it acts like a engine
break till about 3k the spit, sputter. Anyone else
have this problem?
8 Answers
I was thinking possible plugged catalytic converter, may want to have that checked anyway, but the code also indicates that there may be a problem with the fuel pump. Should have the fuel pressure checked. P0191 - Fuel Rail Pressure Sensor Circuit Range/Performance... Possible causes... - High fuel pressure - Low fuel pressure - Damaged FRP sensor - Excessive resistance in the circuit - Low or no fuel - Wiring harness connector of the fuel pressure sensor - Fuel Rail Pressure Sensor - Vacuum leaks - Fuel
Tried disconnecting the harness on the f.p.s. and there was no change on how it ran. Went to the store 10 miles out. Came back out started right up then it started running rough and missing all around now. Hopefully get a fuel pressure gage in the morning but it sounds like there is no easy way to connect to the fuel rail..
If there is no Schrader valve to hook on to with the fuel pressure gauge, (looks like a valve stem in a wheel) you are going to need the necessary fittings to tap into the fuel line. If your are going to rent one, ask in what is required for fittings.
Well there isn't a valve on it for the gauge but used a scan tool and found the fuel pressure was good. Pressure is good till the 2,500 3,000 rpm mark then it drops off, more I push the Gass the more it will drop down to 8psi.
So that could do it. Fuel pressure should maintain within range. Sounds like a weak fuel pump.
Going to try the fuel filter first and hope for a cheap easy fix....
It worked for a little while but problem came back.
