Ok, I just bought a 1983 380 SEL and the engine would turn over, but wouldn't start. With all of my other Mercedes gassers, I would check the fuel pump, fuel filter,fuel relay, spark, disconnect fuel line to fuel distributor, loosen the lines at the top of the distributor to see if gas was getting through and other common problems when having starting problems. I used a jumper to see if the relay and pump are working and everything is good, but When pulling the relay, I noticed some wire disturbances where someone spliced in what is called a "k-loop" that I have no clue about.
There are also some wires that are cut and spliced and also the old wire that was cut was stuffed in between the hood spring in fuse box.
I don't know about the K loop, but there were four wires running to it out of the fuse box. One of the wires was red and look like it came from the fuel relay.when I looked closer the red wire that goes to the K loop was stuck inside the heat shrink protective casing along with the other three wires, but not connecting to anything. Here are some pictures to give you a better idea of this aftermarket mess. My goal is to get this car started and I have a feeling this K loop is the problem, because I have tried everything else.

I think the K-loop is a modification to the K-jetronic injection to give it closed-loop (O2 sensor) control and support a catalytic converter. This is probably a grey market car modified to meet USA smog standards.

As far as I know, K-jetronic injection is mostly mechanical, and will work with the electronics disabled, as long as the pump is running. If you want to rule out the fuel injection, dump a bit of fuel or starting fluid into the intake and see if the engine fires.

Are you sure the engine has spark? You need three things -- fuel, spark, and compression for the motor to run.

I figured it was added because it was a euro model. I can't find any wiring diagrams or anything anywhere. I can't get the car to start.

Try this https://www.google.com/search?q=wiring+diagrams+380sel&gbv=1&sei=g8yVVIrOHZCTyATCs4KgAw

This might do better in the Tech Help section.

Here is a picture

Attached Thumbnails

 

????

Attached Thumbnails

 

I don't think that car is old enough to have K jetronic.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I checked plug #1 and it had white spark. The fuel pump would not run when ignition was in position 3. When I would turn the motor over...the fuel pump runs and spits very strong stream of fuel from the supply hose to fuel distributor(I had it disconnected for the check). I know on my 1989 300se, the fuel pressure regulator had a leak and wouldn't start. I took it off and replaced, then the car ran like a dream and wouldn't stall out when it reached operating temp.
I was wondering where the fuel regulator is on my 380sel and if it could be the culprit??? Please help!

It is 1983 380sel euro

Attached Thumbnails

 

You'd be incorrect -- K-jetronic was used from the 70s through the 90s by various makers. I think the last users were VW and Porsche.

My book refers to the system as the CIS.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

K-jetronic is a CIS (continuous injection system), where the injectors squirt all of the time, and flow rate to them is varied by a distributor. Contrast that with pulsed (D, L, and LH jetronic) systems, where flow is approximately constant, but the injectors open and close briefly to modulate fuel delivery.

I just spent about fifteen minutes looking in the Mercedes Factory service manual for that time period. I found numerous references to a CIS injection system but did not find any references to a K jetronic system. Perhaps you can refer me to the page where that is mentioned....?

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

No idea. Google it - K-jet is a type of CIS, and the term CIS is commonly used to refer to K-jet.

I did. I did not find the googling process convincing so looked at the manual to see what Mercedes called it.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.