knotez1

I do love my Fords but maybe I'm just getting too old. 2004 F150 4.6L STX four door, with 291,000 miles. Out of no where it starts sputtering, rough idle, no power and running very rich ... very. Checked codes indicated MAF, removed and cleaned (electric contact cleaner), cleaned throttle body and intake (throttle body cleaner) and replaced EGR valve and cleaned port (throttle body cleaner). Restarted still just as rich and just as rough. Disconnected MAF and it ran strong. Reset codes, restarted to check codes again, damn still running just as rough. New codes now indicate P0191 fuel rail pressure sensor, P2196 O2 bank 1 sensor 1 and P2198 bank 2 sensor 1. It sounds like process of elimination instead of technology to me. What next fuel pump, fuel pump drive module or catalytic converter ......................... We have also: Changed fuel filter Changed plugs Seafoamed 1/3 in gas, 1/3 in crankcase oil 1/3 through brake booster vac hose Pulled FPDM and it doesn't look bad HELP !!!!!!!!!!! any suggestions or secrets?

bobkyle2

Fuel pump module would be my guess... Just a guess... I don't know what part of the world you are from but the colder weather really kicks these module's in the butt!

Markdas

At that mileage its probably worth changing the FPDM and cleaning the harness connections too. Maybe a good time to do a compression test too, it maybe all good, or you may find some unbalance between cylinders......no way of knowing until you compression test.

I am not sure seafoam is a good idea in through the inlet manifold, ive heard of a few hydraulic locking probelms! But, you did it and seems like all worked okay.

Can you do a fuel pressure test, see what the normal working delivery pressure is and also how much the pump delivers in say 30 secs.

sglover

Possible injector stuck open dumping fuel in. Had this happen on my 05 and did similar. Ran rough and very rich thought it was misfire from a bad coil pack. Injector was the problem squirting fuel in the cylinder constantly.