300SEL 3.5, engine started after 2 years - Page 8 - PeachParts Mercedes-Benz Forum

WANT '71 280SEL · #**106** 12-30-2010, 10:44 AM

Oh, and of course make sure to use fuel injection rated hose as well (it will say on the hose whether or not it is rated for FI).

Regards,

David

werminghausen · #**107** 12-30-2010, 02:27 PM

Quote:

Originally Posted by WANT '71 280SEL

The hoses on the injectors are "technically" a part of the injector but they can be replaced. What you can't see, is the barb on the injector over which the hose slides and has the "collar" holding the hose down. You need to CAREFULLY cut away the "collar" looking piece (again, carefully, meaning you don't go all the way through the hose and damage the barb surface). Once you cut away the "collar" you then pull the hose off as you would any other sort of hose connection. You are then able to put a new piece of hose on using a FUEL INJECTION HOSE CLAMP. Make sure the clamp is fuel injection rated. My final tip is to use the MB hose clamps, not the worm type you see adorn American iron which tear up the hose. Also, the MB clamps pull more uniformly in the circular direction better than the cheap MB clamp knock offs you'll find at your big box auto parts store.Regards,

David

I hope this helps.

Thanks. This indeed helps.
I took off the short stock fuel hose yesterday not knowing exactly what I am getting into.
I realized that this hose w/colalr is part of the injector. I was lucky not to hurt the metal piece with the double edge. Still a few scratches but I think it will be fine- or why are you saying this not damaging the surface?
The fuel hose I have is a Made in Germany, NBR/CR 03/10/51 hose.
I think ID is 7mm and OD is 13mm. Do you think this will do or what is the property of a fuel injection rated hose?
For the clamp I agree. The MB clamps that are on the fuel rail are superior to the other types...no doubt here. I'll use these
Please let me know about the hose or what the correct specification of the hose is.

The injector has another rubber collar secured by a snap ring. Is it wise to replace this rubber piece?

WANT '71 280SEL · #**108** 12-30-2010, 04:24 PM

I'm not sure what rubber collar you're talking about. I think there is a clip that holds the injector body together, in which case you don't want to tamper with that stuff.

The collar I was referring to is the metal piece with a lip at the end of the hose on the injector. If you cut away the metal piece--essentially a lipped ring attached to the injector holding the injector hose--the hose will slide off the injector. Off the top of my head, I don't know the fuel diameter required but it will be the same size FI hose you're using elsewhere under the hood.

Regards,

David

WANT '71 280SEL · #**109** 12-30-2010, 04:31 PM

http://img.eautopartscatalog.com/live/W01331604512BOS.JPG

I'm speaking about the brass colored piece. Put the injector in a vice, and using a hacksaw, carefully cut the brass colored piece off. Looking at the blown up picture you can see where the hose bulges out. That is where the hose slides over a barb, similar to the barb over which the hose slides on the fuel rail.

Regards,

David

werminghausen · #**110** 12-30-2010, 06:22 PM

Quote:

Originally Posted by WANT '71 280SEL

http://img.eautopartscatalog.com/live/W01331604512BOS.JPG

I'm speaking about the brass colored piece. Put the injector in a vice, and using a hacksaw, carefully cut the brass colored piece off. Looking at the blown up picture you can see where the hose bulges out. That is where the hose slides over a barb, similar to the barb over which the hose slides on the fuel rail.

Regards,

David

Thanks David. I understand now how to take this hose piece off.
Do you know the difference between a FI hose and a regular fuel hose?

The rubber sleeve that is hold in place by the snap ring, would you change that?

GGR · #**111** 12-30-2010, 06:39 PM

Have your injectors cleaned and tested by Cruzin' Performance. Good job for a reasonable price.

werminghausen · #**112** 12-30-2010, 07:01 PM

I have removed the intake today. It came out nicely.

air leaks:
-I saw that the screw fitting in the manifold for the brake booster was loose.
-all rubber (injectors sleeves) and conneting rings ('donuts' for conneting the two manifold halves) are old and brittle.
- the 2 gaskets sealing the manifold against the head were good

Many questions come up with the manifold in hand.

1) The problem I have now to get the old gasket off the cylinder head. It is sticking like hell. I fear that I migt damage the head by using sharp tools to scrape it off. Is there a trick to get this old thing off?

2)I have seen the 8 'donuts' which connect the lower and upper halves.
The new ' donuts'/rubber connectors I bought are different in size. The diameter is kind of ok but they are not as long as the old ones. I guess I need to order the correct ones? I attached a picture with the 2 types

3) cleaning the air channels. How is that done best. I think kind of a small chimney brush would be great. There is a lot of gunk everywhere in side the channels.

4) idle speed valve and the other air valve : would you take these off the manifold and inspect and clean? Then I'd possibly need new gaskets here

5) throttle valve switch: Anything to do with this one? I see that it is fixed at the extreme position. Is there a proper adjustment procedure?

6) the 2 long and air channels for idle that pull air from the small holes at the end of intake manifold. Would you open the set screws on either end and clean them out?

7) I believe the rubber line from intake manifold up to the device at the fire wall (don't know what this thing is) was broken or cracked at the bottom and it might have added to the vacuum drop.

Martin

werminghausen · #**113** 12-30-2010, 07:11 PM

Quote:

Originally Posted by GGR

Have your injectors cleaned and tested by Cruzin' Performance. Good job for a reasonable price.

Good idea. They also change the hose. It is about $ 21 per injector.