1977 450SL Fuel delivery type?

[meltedpanda]

Would this have a Kjet or KE Jet?

[RC4U12]

although i dont have this i think the slang is same thing ...K-Jet same as,,,..Jeff

[meltedpanda]

so with or without lamda?

[RC4U12]

Here again i am going from all the reading i do and passing most of the mechanical Fuel injection but you should have a narrow band O2..Jeff

[Gurunutkins]

Hi Jeff and Ron
best i know the 77 is still K Jet without the O2 sensor. I believe that came in with KE around 82 or later (my memory may be out by a year or so but it would be later not earlier). I will send you the other stuff later Ron.
cheers
Barri

[450slcguy]

K-Jet for sure, no lamda. Lamda SL's first appeared in 1980.

[BabyBlueBenz]

You got me interested in learning whether there is a difference, and apparantly there is:

"The KE-Jet system provides quicker response and more precise control of fuel mixture than the K-Jet Lambda system and is the current K-Jet system in use. This system uses a device called a differential pressure regulator to control fuel mixture in response to both engine temperature and oxygen sensor signals. In the KE-Jet system, counter pressure is broken down into primary counter pressure and control counter pressure. Primary counter pressure is the pressure applied to the top of the fuel plunger. This pressure stays constant and is the same as system pressure."

K-Series Fuel Injection Systems
http://www.asashop.org/autoinc/june97/techtips.htm

As I read this, there are three variants...

• K-Jet
• K-Jet with Lambda
• KE-Jet

Wikipedia has a nice timeline of Jetronic family: http://en.wikipedia.org/wiki/Jetronic

In an attempt to answer the OP's question, according to UnwiredTools' UTCIS Engine Management Application Guide (http://unwiredtools.com/manuals/UTCIS_Application_Guide_A2.pdf) page 7:

"On lambda equipped cars (1980 and later)..."

Yet the Google Book Review preview for How to Tune and Modify Bosch Fuel Injection (http://books.google.com/books?id=uuT_AwfQY0EC&pg=PA129&lpg=PA129&dq=bosch+jetronic+lambda&source=bl&ots=V0FlJolwo-&sig=kwqODZdQn2yFpvGf_EDzdmWHjmU&hl=en&ei=ujWnSYKpMY-EtgeCvOXcDw&sa=X&oi=book_result&resnum=2&ct=result#PPA42,M1) states on page 42 that "the Lambda sensor was introduced in 1977".

I think you need the engine code to be sure, or else lay eyeballs on the sensor.

[meltedpanda]

great, thanks, trying actually to help another with this car , so I have not seen it to check for sensor. I too saw in the Watson book that 77 was when it was added, but I lean to 450Sl guy and Barri , after 80 for MB's

[RC4U12]

Alright , My lesson for the day..I'll file that in my slowly fading memory...Jeff..

[meltedpanda]

so there is a connector ( doing this by pictures) on the L side of the fuel distributor, when it is plugged in , car will not start, when it is unplugged it starts, could it be the lammda circuit? or other

[Gurunutkins]

if you are talking about the left side as you view the engine from the front and the switch is between the air plate hole and the fuel distributor and on the left (from the front of the engine) of the mixture control screw then that is the air flow sensor safety switch. as the air plate moves down as the engine tries to start and sucks air then it switches off the safety switch which completes a circuit to allow the fuel pump to run. If you unplug it and short across the plug terminals and turn the ignition on then the fuel pump will run non stop.
cheers
barri

[meltedpanda]

Barri, you and MB doc are spot on - that is the switch, however this car will ONLY start if it is unplugged, everything else has been changed and sorted out, or at least that is what I am thinking. I do know a new fuel pump was put on , and will check on the make. Question now is how is this circuit traced and why is it not working? COuld it be the switch or some connection to the starter or fuel pump? Again this is on a 77 450 I am trying to sort out for a friend, I am very familiar with the Djet, not this K jet so I am stumped a bit.

[Gurunutkins]

sorry Ron, led you astray by lying to you in my previous post (politician speak for mis-spoke) if you leave the connector UN jumpered the pump will run all of the time, if you jumper the connector it will not run . guess the brain is going to sleep. I only picked it up this morning when I read your last post and thought "thats what its supposed to do"
cheers
barri

[meltedpanda]

Thanks Barri, I read your mind, but I still gotta figure out why when connected , and key goes on, which should open it , it stays closed as if jumpered?

On another note, take a look at your home emails , got a specific linkage question for you

[david s poole]

that is the fuel pump safety switch works thus,when unplugged and key on fuel pump runs all the time.when plugged there is switch inside unit so that pump stays off until plate is sucked down by cranking on engine.