My 2.6 is being slowly brought back to proper shape after the idiots who fixed the car for the previous owner just made one blunder after the next. A littany, wrecked the belt tensioner, couldnt figure out why the ABS light was on (a 5c fuse in the Over Voltage Protection relay), poorly run cabling, broke the fan shroud mount on the radiator head, left the air cleaner rattling around loose. Idiots, just idiots.

And the fact it just wouldnt idle properly and had hot start issues.

A very knowledgable mate said "Fix em yourself, they'll just unleash their dim pothead apprentice mechanics on it and they'll stuff it up - get to know them and do it yourself"

And Grant is right - they are complex, cramped but straight forward.

There is a 25mm (guess) breather hose (black rubber) running from the rocker cover into the air -cleaner. There should be a very small gauge vacuum hose (clearish plastic) coming out about halway between the r/cover and the a/cleaner. That goes into the the guts of the fuel injection system. They get disconnected because every time the air cleaner holder assembly is removed, this tiny vacuum hose will just come adrift and whammo - idle problems, starting problems, kickdown problems and a very unresponsive 2.6 under the bonnet (hood to you yanks) - connect it up and you got all problems mentioned fixed. I just couldnt believe how much better it drives now. THis may be your problem - I dunno??

 

I just purchased a 1991 190e w/2.6. Your hose that was disconnected was the problem with my car. Awsome free and easy fix. Thank You BigZ!

 

I believe that's not quite correct

On our 190e cars with the KEJet system that small clear hose is not a vacuum hose, but merely a venting hose for any fuel if the fuel pressure regulator fails

References and tests in video


and discussion of the same on the forums

https://www.peachparts.com/shopforum/448453-post6.html

from

https://www.peachparts.com/shopforum...-mpg-help.html

 

You responded to a 15 year old post but you are 100% correct and those hoses are not vacuum hoses. There is a actually a tiny bit of positive pressure because of crankcase pressure. It should have no effect on the running of the engine as long as they are not plugged.

 

Thanks and truthfully it wasn't about the fact that the post was 15 years + old but that for me researching with my car, a 1990 2.6, this post had the wrong sign posts so wanted to correct it for anyone else going down my rabbit hole of research

And yes great references there and agree about your added point 👍

 

Thank you for correcting the miss information. Much appreciated indeed!

Happy Motoring!