Newbie with 260E fuel tank question

[Alpo of the Dogs]

Hi all,

I'm new merc owner and I have question. I recently acquired an '88 260E and I'm in the process of replacing the battery, wires, plugs, distributor cap and rotor. However, I was told by the previous owner (my uncle) that the car only uses and accepts 5 gallons of fuel.

Has anyone ever experienced this problem? I could really use a lot of help as the car has not yet started.

TIA

 

[tom7035]

Hi all,

However, I was told by the previous owner (my uncle) that the car only uses and accepts 5 gallons of fuel.

Has anyone ever experienced this problem? I could really use a lot of help as the car has not yet started.

TIA

(?) I Can't quite understand this part of your query, someone else may though!

 

[Alpo of the Dogs]

(?) I Can't quite understand this part of your query, someone else may though!

The engine only uses five gallons of fuel when the tank is full. As soon as the fuel level guage reads empty, I go to fill it up and the pump only fills the tank with five gallons of fuel. If I don't fill it up once the fuel level is on "E," the car refuses to start.

Is the fuel level somehow related to the starting system?

thanks again for the reply. I really appreciate any sort of clue, or intent to help.

 

[andy_k]

I'd start by putting a new sender unit in as that has obviously failed. Also change the filters as well.

Just because it says it's empty shouldn't stop the car if the tank is actually full.

 

[Ramius]

I agree with changing the filters. Amazing how much difference is made when they are as new and not clogged. A lot of running issues are related to the fuel filters on these.

 

[Alpo of the Dogs]

So I was able to get the car started after changing the spark plugs. After having it idle at 2000 rpm (by using a brick on the throttle pedal) I started to use a "3-step-commercial-fuel-injection-system-cleaning kit"

The car starts up now, only when it's in neutral. Sometimes it will start in P after it's run after a while.

Also, the fuel tank (which was near empty) would only accept 1.5 litres of fuel, even though it was nearly empty. Can someone explain to me how the Mercedes fuel tanks operate? The fuel gauge showed full, even though I know for sure that the tank was nearly empty. Any tips anyone?

Also, who makes a good big brake kit for the W124 chassis? And what performance parts are available for the m103 engines?

 

[Stevie A]

How can the fuel tank be empty but only accept 1.5 litres???? You won't go far between petrol stations


Sounds like either the fuel guage is gone and / or there's a blockage or something in the fuel delivery to tank / tank / fuel system surely?

How do you check a faulty fuel tank etc though? I don't know. Any experts know?

 

[Alpo of the Dogs]

So I've been told that I should check the fuel tank vent. I'm assuming that the fuel tank vent leads to the carbon cannister? What do you do if the cannister is full? Doesn't it just drain out onto the road? I can't find that cannister anywhere in the engine bay. If someone could tell me where the carbon cannister is located in an '88 260E that would be very helpful.

Thanks in advance!

 

[tom7035]

So I've been told that I should check the fuel tank vent. I'm assuming that the fuel tank vent leads to the carbon cannister? What do you do if the cannister is full? Doesn't it just drain out onto the road? I can't find that cannister anywhere in the engine bay. If someone could tell me where the carbon cannister is located in an '88 260E that would be very helpful.

Thanks in advance!

I think it is under the N/S/F (left) wing, covered by the splash guard.

 

[Alpo of the Dogs]

I think it is under the N/S/F (left) wing, covered by the splash guard.

what's N/S/F stand for?

 

[andy_k]

Near Side Front - passenger side

HTH

Andy

 

[Ian Brown]

n/s/f stands for near side front which is the passenger side if it's a right hand drive. you say the tank only holds five gallons have you checked the tank to see if it has been pulled in by a vacuum problem in other words does the tank look as if it has a big dent in it

 

[Alpo of the Dogs]

oh ok! Actually the tank is fine. I think it's actually the carbon cannister. I read on another forum that someone with a C-class was experiencing the same problem and he replaced the carbon cannister. Another person on another forum had the same problem with his Chevy Impala, and he shot compressed air into the cannister's inlet line and that seemed to solve it.

Otherwise, I suppose I could go buy a new carbon cannister.

 

[Stevie A]

Alpo - I think the carbon cannister is just for exhaust emissions reduction. I don't know if it is in the fuel line system. So I think you are barking up the wrong tree with that.

Any expert know what the carbon cannister does?

 

[andy_k]

nah, well, not as far as I understand it (although I'm happy to be told I'm wrong) it works like this......the carbon cannister is to stop the emissions from evaporated fuel, in the good old days car's had vented filler caps which allowed evaporation straight into the atmosphere - apparently that's not that good for the environment so fuel systems were "sealed" and the emissions were allowed to escape - usually through a vacuum controlled purge valve (only open when the engine is running) into a carbon filter which took out all the nasty pollutants.

Whether or not a blocked carbon cannister would cause the problems here, I doubt it but it's worth changing just in case it's a contributory factor.

Most Mercs are a pain to fill with fuel, have you tried running the pump a bit slower or inverting the pump nozzle?

I must admit unless there is some physical blackage in the tank I'm struggling for ideas on this one

HTH

Andy

 

[Stevie A]

Cheers Andy - Glad I know what the carbon cannister is for now.

 

[Alpo of the Dogs]

nah, well, not as far as I understand it (although I'm happy to be told I'm wrong) it works like this......the carbon cannister is to stop the emissions from evaporated fuel, in the good old days car's had vented filler caps which allowed evaporation straight into the atmosphere - apparently that's not that good for the environment so fuel systems were "sealed" and the emissions were allowed to escape - usually through a vacuum controlled purge valve (only open when the engine is running) into a carbon filter which took out all the nasty pollutants.

Whether or not a blocked carbon cannister would cause the problems here, I doubt it but it's worth changing just in case it's a contributory factor.

Most Mercs are a pain to fill with fuel, have you tried running the pump a bit slower or inverting the pump nozzle?

I must admit unless there is some physical blackage in the tank I'm struggling for ideas on this one

HTH

Andy

Andy, bless you and your logic! Well, I'm sad to say that I'm 220 miles away from my car, and I will not be able to see it for another two weeks. Next time I see it I will definitely try to invert the pump nozzle. I suppose I'll just sit here and speculate.

This is where I go to my other thread