92 F150 Fuel supply problem, HELP
Thread Starter
|
New User
Joined: Mar 2005
Posts: 3
Likes: 0
92 F150 Fuel supply problem, HELP
My f-150's engine stumbles through out the RPM range. I have duel tanks and the stumble is similar to when a tank is nearing empty (air in fuel lines).
I was getting a O2 sensor code lean prior to current problem, but at the time the engine was loading up with fuel and consuming twice as much gas than normal. Replaced O2 sensor and no longer too rich. The stumble does not seem to be dependent on engine temp or a particular driving condition.
I check fuel pressure in rail koeo, koer, no regulation and checked out to be ok. Noticed a lot of air/gas bubbles coming out of fuel rail (shrader valve removed), hooked up clear tubing to fitting. Watched bubbles come out for several minutes (fuel tank caps open). Cycled the fuel pump many times to get clear fuel flow (no bubles). I have removed the valve before on this truck and other fords, seemed to be alot of compressed gas in fuel lines. The engines seems to run like there is air getting injected along with the fuel. Happens regardless of which tank I am using. Rear tank has small leak don't normaly use it, run on front tank most of the time.
Done the following: fuel filter change, MAP ok, TPS ok (WOT, was 850 ohms, high, but seems ok), EGR blocked with plate between valve and manifold, due to rotted out pipe from exhaust (would not think this is causing problem)
Anyone have any ideas??????????
Jim
I was getting a O2 sensor code lean prior to current problem, but at the time the engine was loading up with fuel and consuming twice as much gas than normal. Replaced O2 sensor and no longer too rich. The stumble does not seem to be dependent on engine temp or a particular driving condition.
I check fuel pressure in rail koeo, koer, no regulation and checked out to be ok. Noticed a lot of air/gas bubbles coming out of fuel rail (shrader valve removed), hooked up clear tubing to fitting. Watched bubbles come out for several minutes (fuel tank caps open). Cycled the fuel pump many times to get clear fuel flow (no bubles). I have removed the valve before on this truck and other fords, seemed to be alot of compressed gas in fuel lines. The engines seems to run like there is air getting injected along with the fuel. Happens regardless of which tank I am using. Rear tank has small leak don't normaly use it, run on front tank most of the time.
Done the following: fuel filter change, MAP ok, TPS ok (WOT, was 850 ohms, high, but seems ok), EGR blocked with plate between valve and manifold, due to rotted out pipe from exhaust (would not think this is causing problem)
Anyone have any ideas??????????
Jim
Posting Guru
Joined: Jun 2004
Posts: 1,781
Likes: 1
From: Central NY
I can't think of anything that could pump air into the lines that are at 39psi except the fuel pumps themselves.
Are you getting any other codes out now? And have you cleared the computer so it relearns how to run?
Are you getting any other codes out now? And have you cleared the computer so it relearns how to run?
Thread Starter
|
New User
Joined: Mar 2005
Posts: 3
Likes: 0
new code
I did get a new continous code while driving today, # 96 book says fault between fuel pump and PCM. Now wondering exactly what that indicates, wiring short, bad fuel pump. I reset ECM after O2 sensor install (battery disconected for over 1 hour). I may connect pressure gage to fuel rail and drive around, check for drop outs.
Posting Guru
Joined: Jun 2004
Posts: 1,781
Likes: 1
From: Central NY
Per Fordfuelinjection.com ...
Fuel pump secondary circuit failure. The EEC did not sense battery voltage on the Fuel Pump Monitor circuit.
Possibly an intermittant connection or a wire about to break?
Good luck and keep us posted.
Popa Tim
Fuel pump secondary circuit failure. The EEC did not sense battery voltage on the Fuel Pump Monitor circuit.
Possibly an intermittant connection or a wire about to break?
Good luck and keep us posted.
Popa Tim
