Hey everyone
so i have had an issue with fuel pump not priming and the car not starting. I replaced fuel filter , which was filthy…it was starting fine for some time and now the issue is back. I replaced fuel pump rellay and checked the fuse. Any ideas?
ps. I recently had looped rail installed with other things like 172 crank pulley 84 sc pulley 82mm tb and cooling

 

What is the fuel pressure reading ?

 

Did you replace the relay and fuse for your AMG that is hidden under the panel on the right hand side of the trunk or did you replace the relay and fuse for the intercooler pump located in the rear SAM? AMG and non-AMG have different electrical harnesses, relays, and fuses. Fuel pump electric system is not similar between them.

 

Any update?

 

75psi at idle

 

yes rellay on the passenger side trunk by reservoir
fuse looked fine. There socket looked fine as well.
it’s weird because evetyally starts but it sound like pump is wining and sometimes interior lights are flickering. I wonder if weak battery could contribute to my issue. But one thing that i dont get, it either works or it doesn’t right! Well not in my case. Sometimes it starts right up, sometimes it takes wigling the key 10000 times until i hear it prime. And then it goes

 

Did you replace the whole sender unit, or did you replace the actual filter? Is the starter cranking? I'm not following the key wiggling comment??

I got a feeling your going to have to go back in the tank and check the hose connections and visually watch the pump and sender when it's energized.

My first guess is the fuel hose did not snap on properly (ask me why I think that )

Flickering interior lights (if your battery / connections and grounding strap are good) is usually the voltage regular brushes are worn.

 

i just replaced the filter of course. Initially mb dealer replaced fuel tank and components under warranty… couple years after it started happening and thats why i went to replace a filter. Everything under there is solid now. I triple checked. It’s something that doesn’t make it prime sometimes. So i have to wigle the key 1 pos to 2nd few times

 

so you did this procedure ?......https://mbworld.org/forums/w211-amg/...er-insert.html

Ok your trying to prime by turning the from position 1-2... Have you put a test light on it? or are you only listening for the pump sound? Now it's sounding more electrical. Barry is the man and has gone through the up grades in the electrical.

Try pulling the fuse ( I know it looks OK) and polish the blades with some very fine sand paper. Then get a nail file and clean up the fuse holder where the blades make contact. Assemble and try.....

 

I think you need to explain things a little better.
Let's assume that you are not listening to the pumps at all. When you go to start the car the engine is spinning over but does not start correct ?
At this time you are seeing fuel pressure when trying to start the engine correct or not ?

 

correct. At that moment i dont see pressure. I assume there is none. But i could double check that as well… sounds like computer doesnt always send signal to the pumps to prime… weird

 

Info for the '03 to '05 E55. The '06 E55 uses two relays with each having a separate connection to the Motor Electronics (ME). Tap into the lines for the fuel pumps (or the trigger signal for the relay) with a multimeter or led or light and you should see it activate for approximately one second when the key is turned on. The fuel pump circuit then turns off until the ME "see" a signal from the crank position sensor indicating the engine is turning over (safety feature in case of a wreck so the fuel pumps do not continue pumping fuel into a possibly compromised fuel system and causing a fire). Fuel pressure gauge can provide additional verification.

If your fuel pumps are part number ending in 00-00, pins 1/2/3/4 are: -/+/+/-.

If you have an '06, I'd have to look up the information again. I posted on it (IIRC) in "E55 fuel pump relay and fuse maintenance".

 

yes is did exactly that procedure, it was workin fine after that. And now its doing it again…

 

i have 05 e55. Thank u for the information, i will look into it. Im not great with wires and multimeters but i think I understand what u saying

 

Do u think the crank position sensor could be an issue?

 

Possible. I realize STAR/Xentry is supposed to diagnose the CPS but I have had a failing CPS that did not show in Xentry.
Throw a multimeter on the fuel pump connector under the back seat and watch it over your shoulder when you turn the key on. It will distinctly show 12 volts for approximately one second and then drop to zero. If no primer pulse there back up to the fuel pump relay and place the leads across the input and output of the relay trigger. It's an open collector circuit that the ME connects to ground to allow current to flow through the solenoid coil. If the ME is working correctly, you'll see 12 volts across the input and output leads of the solenoid when the ME connects the output to ground (voltage drop across the coil) when your helper turns the key on. You should see 12 volts between the output and chassis when the ME is off at all times as the open collector circuit is isolated from ground.
Internet search on open collector will explain it better.

 

ok i understand. Thank u

 

If you're not holding residual fuel pressure (when you do get a reading) You're going to have to check your work on the sender filter replacement. I have had the top pop off because it was not secured back on properly

 

Or.... the o-ring for the filter hat is damaged and leaking ???

 

Absolutly!

 

Hey everyone
I drive a truck for a living so im gone for s week

before i left, the car completely stopped starting .
i turned the key 1-2 position 100x times. Pump doesnt prime anymore.

i think i will start with crank sensor when i come back

 

And you know it doesn't prime because......?
Have you tested for spark? A simple in-line type are cheap. You can also try the shade tree mechanic( side of the road) technique. That is highly controversial. You know you have no fuel but your starting with spark?

 

You need to know if there is pressure when you try and start it. You are assuming things and you really need hard facts to diagnose anything. I still have not read from you a diffinitive reply as to fuel pressure readings when you do the "wiggle" of the key.

 

pressure was 75 psi at idle and 60psi before starting
what u mean im assuming things…

 

So there ya go. That's the first time you said it shows 60psi when key cycled before it starts.So.....it is not a fueling issue. If there is at least 45psi pressure when trying to start ,then it will fire up.
So it's a no start but cranking and I would lean big time towards the crank sensor. Easy to change and make sure you get a Mercedes or Bosch replacement if you decide to replace it.