190E 2.6 - Replacing Air Guide Housing

[higher planes]

Hello Gentlemen! Few quick questions for you all... I'm trying to replacing the leaking rubber air guide housing on my 1992 190E 2.6.

1. Before disconnecting all the fuel lines, do I need to relieve fuel system pressure?

2. Because I'll be removing all the fuel lines from the fuel distributor, when I hook everything back up, am I going to have to re-adjust the fuel or air mixture?

Thanks!

[lsmalley]

Air guide housing?

[higher planes]

Whatever this thing is called...

[lsmalley]

Originally Posted by higher planes

Hello Gentlemen! Few quick questions for you all... I'm trying to replacing the leaking rubber air guide housing on my 1992 190E 2.6.

1. Before disconnecting all the fuel lines, do I need to relieve fuel system pressure?

2. Because I'll be removing all the fuel lines from the fuel distributor, when I hook everything back up, am I going to have to re-adjust the fuel or air mixture?

Thanks!

Ok, just wondering if you were referring to something else. My question is: why would you need to unhook all the fuel lines and releive the fuel system and then readjust fuel/air mixture? Is that really necessary or are you doing something else?

[higher planes]

Originally Posted by lsmalley

Ok, just wondering if you were referring to something else. My question is: why would you need to unhook all the fuel lines and releive the fuel system and then readjust fuel/air mixture? Is that really necessary or are you doing something else?

Okay... I'm trying to change the air guide housing. I'm asking IF I need to relieve fuel system pressure to change it. I don't know, that's why I'm asking.

And I thought you needed to unhook all the fuel lines to get to the air guide housing. Is there an easier way?

[lsmalley]

All you need to do is unbolt the 4 nuts, disconnect 1 plastic tube going to the crankshaft, and remove it. The picture shown looks like a newer version of the original one because even when I tried to order the OE one I have, that picture came up. Can you post a picture of what yours looks like? It literally is like a 10 minute jobif we are both talking about the same thing.

[higher planes]

Originally Posted by lsmalley

All you need to do is unbolt the 4 nuts, disconnect 1 plastic tube going to the crankshaft, and remove it. The picture shown looks like a newer version of the original one because even when I tried to order the OE one I have, that picture came up. Can you post a picture of what yours looks like? It literally is like a 10 minute jobif we are both talking about the same thing.

I don't have a camera right now, but here's basically the same exact thing from the tech manual...

[lsmalley]

Ok, so we were talking about 2 totally different things. I'm not sure. I would have to defer your question to someone with a bit more experience as I have never done that job. Anyone care to chime in?

[JohnM.]

The system will relieve itself, so to speak, when you disconnect the main gas line to the fuel distributor. You will lose a little gas, but not much, just loosen all lines slowly until you've relieved pressure.

In a perfect world, you should not have to change the mixture/CO. UNLESS someone has already adjusted the mixture to compensate for the cracked/leaking air guide housing.

[higher planes]

Hi JohnM, thanks! That helps. One more question, would it be fine to remove the fuel lines from the injectors only, or do I have to remove them from the distributor as well?

[JohnM.]

Yes, I'd say the safest/easiest would be to remove the lines from injector only. There are only 3 10mm nuts holding the FD assembly in place, plus the clamp on the air guide housing. Most of the work is disconnecting the fuel/electrical lines.

[higher planes]

Awesome!

[higher planes]

Just tried loosening the fuel lines from the injectors. I mean I don't want to damage any of the lines, but how much force do I have to apply to loosen those lines? Seems like I can't get them to come off. Is there a trick?

[JohnM.]

Be sure to hold the allen set screw while loosening the lines. It can take a good amount of force. Make sure your wrench is on there solid, and you can put your entire body weight into it. Or use another wrench over the end as a leverage "cheater".

[higher planes]

Thanks man! I got it. Pulled the mixture control unit, but upon inspection of the air guide housing piece, I don't see any cracks, yet there's oil/fuel residue all around the circumference where the AGH attaches to the throttle valve. So I'm a little baffled. And I'm pretty sure the clamp was on tight. Where is that oil reside coming from anyway?