HELP- fuel guage issue, replaced Fuel Sender and Fuel Pump...
02-05-2018, 05:12 PM
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2010 E550 4MATIC (W212+273 engine)
HELP- fuel guage issue, replaced Fuel Sender and Fuel Pump...
ok so I have a 2010 E550 4 matic...93k miles. Had fuel pressure issues and false fuel level reading at empty, so replaced both fuel pump and fuel sender units (right & left). I completely emptied the tank during repair and added 5 gallons of fuel after repair..everything was awesome for a day, gauge was reading perfectly...however now fuel guage will show fuel level at start up then just fall to zero after a few seconds then it will just not register anything until it sits overnight, total head scratcher. I have not added any additional fuel yet in case I have to open it up again but here is what i have tried so far...
1. Re-checked wire harnesses and connectors...all appear to be good
2. Checked & removed both instrument cluster fuses, hoping for a reset...(read that on another thread)
3. opened fuel cap to let vapor out (read that on another thread)
I know the new units are installed correctly beacuae the fuel pressure is holding rock solid at about 50psi at idle and 4krpm and the car is running awesome. I know the connectors are all correct because the fuel level was showing perfectly while driving for about 30 minutes after the repairs were completed multiple restarts. I feel like I am grasping at straws right now so any expert advice or insight would be most welcome!
1. Re-checked wire harnesses and connectors...all appear to be good
2. Checked & removed both instrument cluster fuses, hoping for a reset...(read that on another thread)
3. opened fuel cap to let vapor out (read that on another thread)
I know the new units are installed correctly beacuae the fuel pressure is holding rock solid at about 50psi at idle and 4krpm and the car is running awesome. I know the connectors are all correct because the fuel level was showing perfectly while driving for about 30 minutes after the repairs were completed multiple restarts. I feel like I am grasping at straws right now so any expert advice or insight would be most welcome!
02-06-2018, 04:23 PM
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1922 Ford Model T / no OBD
Is that happening regardless if you have full tank or 1/2 ?
You need to understand tank system as in W211 it is complicated.
You don't have fuel pump and fuel sending unit.
You have 2 pumps with 2 level sensors.
When 1 pump is electric and supply the engine, the other is using returning fuel with Venturi pump to transfer the fuel from passenger side tank to driver side, where main pump can use it.
Your symptoms are pretty hard to interpret, but I would check connections on fuel level sensors before opening the tank again.
How did you conclude it was working correctly after restart when you never put more than 5 gallons?
You need to understand tank system as in W211 it is complicated.
You don't have fuel pump and fuel sending unit.
You have 2 pumps with 2 level sensors.
When 1 pump is electric and supply the engine, the other is using returning fuel with Venturi pump to transfer the fuel from passenger side tank to driver side, where main pump can use it.
Your symptoms are pretty hard to interpret, but I would check connections on fuel level sensors before opening the tank again.
How did you conclude it was working correctly after restart when you never put more than 5 gallons?
Last edited by kajtek1; 02-06-2018 at 04:25 PM.
