Hi all,
I just recently bought myself a '84 190E 2.3 which comes with its issues. I took it to a MBZ dealership to look it over and they say I need a Fuel Level Sensor as the car died on me because of no gas while gauge was still reading about a quarter tank left. Upon doing research, I was able to find 3 different part numbers but are worded differently and I am not sure which to get in this situation. #2015420304 is listed as the Fuel Tank Sending Unit but if you add a 64 at the end (#201542030464) I come up with a Gauge Sender Unit and then finally the last part number I found was #2015420104 which shows as a Fuel Level Sensor. I understand the last number is in the name of which I was told to get but different mechanics provided the first two-part numbers and say THAT'S the part I need. If I can just have clarification on which is the correct part, it would be greatly appreciated as finding anyone who works on these cars in Los Angeles is already showing to be a struggle!

 

Yes, I hear you on the mechanics available/willing to work on these 80's mercedes.

However let take a step back. What is wrong with your sender unit. Let me guess:
(1) The gauge is jumpy across the range. sometimes or always shows zero
(2) The warning light does not even light up on empty (so you ran out of gas)

If so, the solution to this is to first obtain the two O rings necessary (to seal against the tank) to be replaced from the dealership.
Then to take your sender out to clean the built up gum around the contacts carefully. It is a 15 minute job.
You can use a cotton swab and ball and break parts cleaner or electrical contact cleaner to to so. Make sure you clean the base where the "empty" contact is.

You can also save yourself $200 or the trouble to find a sender for the very early production model year.

-Cheers!

If you have a truly busted sender, you can ignore my comments.

 

Sounds like the issues are within the ballpark. I bought the vehicle and within literally 45 minutes of driving back home, the gauges started to go wonky and wasn't able accelerate with the gas pedal before I pulled over and died. When I tried cranking, it'd the gauge would jump around to half, then below half and stood within that range, but never able to start. And yes, light indeed did not come on as the gauge read I still had gas left in it. Which O rings would I need to replace if I were to remove and clean it?

-Thanks!

 

Are you sure you are just out of gas? It sounds like you have other electrical issues. Most likely oxidized/corroded contacts of various electrical circuits. Car is over 40 years old so not too surprising.
So the car started after you fueled up?

Hopefully the car has been in southern California all it's life so the corrosion would be at a minimum but that is a strong function of where it was kept and whether it was close to the pacific coast or not.

If you come to the conclusion that all you need is just the fuel sender, whether it is new or just cleaned you will need the o rings in the following picture. Straight out of my 36 year old parts book.
Parts are labelled 29 and 32. Dealership will have them. You will have to clean the aluminum surfaces, otherwise you will get a fuel leak on a full tank.

 

I am not too sure if it's just that. That is at least what the dealership themselves said as of now. Considering they don't have the part available; I just have to order it on Ebay and pray that fixes the issue since I don't always have direct contact with them. They also mentioned earlier today that there might be a possible parasitic draw happening as the battery keeps needing to be charged. I first suspected it could've just been a faulty alternator when this whole issue first happened as the battery was recently replaced but not the alternator but like I said I don't always have contact to get constant updates and I myself have not dealt with an older car like this before. But to answer your question, it did start up after they fueled it up about 5 gallons.

 

For your sake, I'm hoping that you are a DIY person. Otherwise you will be spending a fortune to make this new acquisition road worthy.
We can help you here if you are DIY'er. If not it will be difficult and expensive.