2004 Mountaineer keeps dying and has to be towed home! First gas gauge goes below zero, second mpg goes to 6 or less than dying while driving! HELP!

[mizzej]

2004 Mountaineer keeps dying and has to be towed home! When problems started first thing gas gauge went to below zero but kept running, second mpg goes to 6 or less for few months then started cranking slow and sometimes had to jump off then started dying while driving! Finally died and had to be towed home. I’m in desperate need of the vehicle because I’m 100% Disabled Vietnam Veteran. HELP! I’m located in Central Alabama so not extremely cold. Has V8 / AWD with 200K miles. Had problem few years ago and replaced fuel pump, computer, all O2 sensors and all modules I could find. Has relatively new alternator and battery but had both checked and they check to be good. Can’t find any bad fuses. When had problem in past quit driving for a few years but then it started running fine for a few months then started having these problems.

 

[Mbrooks420]

6mpg for a few months? Sounds like a major issue, possibly a stuck injector. Dumping that much fuel in will ruin the cylinders, and also the cats.

I’m assuming the check engine light is always on. Does it ever blink?

Pulling the plugs will tell you more about what’s going on in the top end.

Does the oil smell like gas?

 

[mizzej]

Thanks for the reply. Yes, the check engine light is always on but doesn’t blink and the oil doesn’t smell like gas. I’m out of town now so can’t pull the plugs but will when I get back home and will post what I find.

 

[J_C]

Cranking slow, needing jumped, and dying while driving suggests to me that you probably have an electrical problem, so I would measure whether the alternator is putting out ~14.4V while running, put the battery on a charger and see if it runs well right after pulled off the charger at full charge, though if the battery has been sitting at a reduced charge level for months, it's probably compromised and needs replaced. Check the battery voltage right after the engine is shut off, and then after the vehicle has not been running for a few hours, should stay around 12.6V.

Also check the more obvious things like loose battery cable clamps, corrosion on battery posts or the wire to battery clamp, bad chassis ground point, bad alternator wire or connection at alternator.

Next I'd use a scan tool to pull trouble codes, and then look at realtime data if you can keep it running.

After doing all the above, I might have both the battery and alternator retested. I know you stated that was done already, but something is fishy.

 

[mizzej]

I was finally able to pull the codes … 1) P0463: Fuel Level Sensor A CKT High Input, 2) P0606: PCM Processor Fault, 3) P2100: Throttle Actuator Cntrl Motor CKT / open, 4) P2106: Throttle Actuator Cntrl System Forced Limited Power, 5) P2107: Throttle Actuator Cntrl Mod Processor & 6) P2110: Throttle Actuator Cntrl System Forced Limited RPM.

 

[Josh P]

I'd look at the wiring harness for the engine and throttle. Pretty common problem for the insulation to disappear with age.