04 E55 AMG Mercedes changed fuel pump module now car tries to die if I give iit gas
Well thanx you for the advise how do I go about moving it? Would I just copy and paste it to the other forum and erase this thread all together?
My apologies for any inconvenience.




-Put a fuel pressure gauge on the rail. Tape it to the windshield. Take notes.
-Possible causes:
---One of the two fuel lines popped off of one of the fuel pumps. You'll have to open the tank to confirm. Two bars or less on the fuel gauge or fuel will spill into the passenger compartment.
---Pull the panel on the passenger side of your trunk and inspect the fuel pump relay and socket. Replace the relay even if it looks good.
---Pull the rear seat, pull the access cover, pull the connector, ensure the contacts molded into the plastic lid are not melted. If yes, replace.
---If the fuel tank is open, verify the return lines from the filter/regulator still feed the passenger side of the fuel tank.
Remember, 78-82 psi at idle. A few pounds less at full throttle and maximum rpms; if pressure drops into the 40's or 50's, one pump is not running or is wired backwards. It is always possible you received a bad set of fuel pumps.
If fuel checks out okay, start looking for an air leak in the intake system. At the same time, scan the car to see if a digital sensor/module failed (e.g. the pedal sensor). Unlikely but I literally had a manual clutch function in the morning and fail at the dealership a couple of hours later. I ripped into the service manager about his mechanic trying to rip me off and ended up buying two boxes of donuts for the mechanics because the clutch literally failed between the time I dropped it off and went to pick it up. I know this because I was so pissed off I had the car towed home and pulled the transmission myself...oops. My bad. How about some donuts for your mechanics and a sincere apology?
Good luck and let us know what you find.
EDIT: PM a moderator and they can move the thread for you.
Last edited by bbirdwell; Jun 25, 2019 at 09:39 PM.
-Put a fuel pressure gauge on the rail. Tape it to the windshield. Take notes.
-Possible causes:
---One of the two fuel lines popped off of one of the fuel pumps. You'll have to open the tank to confirm. Two bars or less on the fuel gauge or fuel will spill into the passenger compartment.
---Pull the panel on the passenger side of your trunk and inspect the fuel pump relay and socket. Replace the relay even if it looks good.
---Pull the rear seat, pull the access cover, pull the connector, ensure the contacts molded into the plastic lid are not melted. If yes, replace.
---If the fuel tank is open, verify the return lines from the filter/regulator still feed the passenger side of the fuel tank.
Remember, 78-82 psi at idle. A few pounds less at full throttle and maximum rpms; if pressure drops into the 40's or 50's, one pump is not running or is wired backwards. It is always possible you received a bad set of fuel pumps.
If fuel checks out okay, start looking for an air leak in the intake system. At the same time, scan the car to see if a digital sensor/module failed (e.g. the pedal sensor). Unlikely but I literally had a manual clutch function in the morning and fail at the dealership a couple of hours later. I ripped into the service manager about his mechanic trying to rip me off and ended up buying two boxes of donuts for the mechanics because the clutch literally failed between the time I dropped it off and went to pick it up. I know this because I was so pissed off I had the car towed home and pulled the transmission myself...oops. My bad. How about some donuts for your mechanics and a sincere apology?
Good luck and let us know what you find.
EDIT: PM a moderator and they can move the thread for you.
Thank you for the advice Birdwell, I'll get right on that. Just picked up the fuel pressure test kit, so I should be able to complete that shortly and get back to everybody with what I have found.
-Put a fuel pressure gauge on the rail. Tape it to the windshield. Take notes.
-Possible causes:
---One of the two fuel lines popped off of one of the fuel pumps. You'll have to open the tank to confirm. Two bars or less on the fuel gauge or fuel will spill into the passenger compartment.
---Pull the panel on the passenger side of your trunk and inspect the fuel pump relay and socket. Replace the relay even if it looks good.
---Pull the rear seat, pull the access cover, pull the connector, ensure the contacts molded into the plastic lid are not melted. If yes, replace.
---If the fuel tank is open, verify the return lines from the filter/regulator still feed the passenger side of the fuel tank.
Remember, 78-82 psi at idle. A few pounds less at full throttle and maximum rpms; if pressure drops into the 40's or 50's, one pump is not running or is wired backwards. It is always possible you received a bad set of fuel pumps.
If fuel checks out okay, start looking for an air leak in the intake system. At the same time, scan the car to see if a digital sensor/module failed (e.g. the pedal sensor). Unlikely but I literally had a manual clutch function in the morning and fail at the dealership a couple of hours later. I ripped into the service manager about his mechanic trying to rip me off and ended up buying two boxes of donuts for the mechanics because the clutch literally failed between the time I dropped it off and went to pick it up. I know this because I was so pissed off I had the car towed home and pulled the transmission myself...oops. My bad. How about some donuts for your mechanics and a sincere apology?
Good luck and let us know what you find.
EDIT: PM a moderator and they can move the thread for you.
That now I have a completely different problem and I know that I am just making myself look like a huge idiot but you seem to be a very knowledgeable person when it comes to these cars, so I figured I'd ask for your help. The other day I messed with the secret climate control menu, i changed one of the values in the menu on accident and I'm not sure which one it was.
But now my cooling fan is not coming on so I'm guessing it has to do with me messing with the secret menu.... the fan was running fine before , now it's not. is there any way you can save the day again...
Thanx for everything


