What you found loose isn't a vacuum line BUT a fuel bleed off line that connects to a breather hose. ONLY there in case the fuel pressure diagram develops a leak.


As far as the wire goes...either a picture OR a part number off of the connector.


Still, most common HOT soak starting issues are fuel pressure bleed-off related.
And whether or not the ignition system has enough spark to get the job done.

David, as MB Doc notes the line from the fuel pressure regulator connects to the underside of the breather hose at the valve cover. It's possible this line has become brittle with age and a portion has broken off. Your local MB dealer sells replacement white, plastic tubing. Be careful not to break off the short rubber connector that protrudes from the fuel pressure regulator if/when you replace the plastic tubing. New FPR's are quite expensive.

Update
 

Hey guys, thanks for the continued support. Its pouring down raining here, so i didn't get a part number from the wire, and I couldn't get a digital photo, so I made a sketch in hopes that someone may know where this wire is supposed to connect. I emailed the .pdf sketch file to M
B Doc because it was too large to post here.

What does that plug look like? I forget where the coolant temp sensor is on an m104, but what you are describing sounds exactly like the temp sensor plug on a m103. On a 103, it goes to the coolant sensor at the rear of the block right next to the valve cover....


I'll have a look in WIS and see if I can uncover what it is....



-tp

it is a cylindrical rubber boot about 2" long, sheathed with corrugated plastic...the wire is solid black...inside the boot is a single round female terminal (metal) the kind that plugs onto a round male pin terminal.

fuel accumalator .
do replace .sorted my problems
mak

The short rubber FPR hose is replaceable and available from the dealer.

Where is the fuel pressure accumulator on the 300CE (M104)? Is it a difficult job to remove and replace?

Quick Warm Starts
 

I recentered the air flow sensor plate; Two warm starts today so far...I am going to test it again here in a bit, but I think that must have been it. The computer was telling the fuel system that it needed fuel to go with the air coming in (but not really), so basically I've been starting a flooded engine as you guys mentioned to me earlier. Thanks for all the help with this matter. Again, you guys have saved me alot of $$$$$$$$$.:D