76 or there about was the switch..

CIS was a brick $hit house of reliability when compared to D-Jet...it will suffer So much neglect keep on working.

I figure benz had CIS/CISE pretty well nailed down as well or better then anyone..stick w/ what you know/don't fix what isn't really broken. Emissions, power, efficiency were what drove them to LH, ME etc..

 

It was an emissions push mostly right?

It surprises me that there are K-Jets without O2 Sensors?
Not sure how the EHA knows whats going on without one.

Once it is setup, works pretty darn good.

 

Yeah, 1st gen Aussie cars didn't have O2 sensors or EHA valves. I think that the UK and most of Europe was the same.

Do the CIS injectors spray the fuel better than electronic?

 

Mercedes? You will find the same basic CIS in a Volvo of the same vintage. The beauty of CIS is it is so absolutely simple. Air pressure on the metering plate opens the metering valve and that sends gas to the injectors. Except for the warm-up regulator and cold start valve, both of which do not operate at normal engine temperature, there's noting else to it. You can tune it on the side of the road or anywhere with a 3mm allen wrench.

 

Form what i heard the mechanical K jet injectors spray in a conical shape (similar to most EFI injectors for a single intake valve engine). also air shrouding helps in atomizing the fuel of k jet. (can i actually use the word atomizing for FI?)

check out page 17 in this.
Bosch K-Jetronic Fuel Injection Manual

only problem is that ALL of the injectors are firing at the same time which hurts fuel economy.

oh and check out Not2Fast: EFI Ramblings for different spray patterns of efi.

 

new EFI injectors have many, I think 8 or so...Tiny holes that do a Very nice job of atomizing the fuel...i doubt the CIS injector would be superior.

The New New stuff is getting into multiple triggers of the injector each stroke.. Cool stuff.

Firing all the time indeed...:-/

 

I watched my new and old CIS injectors on the test bench and it is pretty crappy.
Especially at low power when there is just enough pressure to barely crack open the poppet and fuel sprays out.

There is just a lot of ways that can go wrong and so the spray pattern isn't great even new. Higher power they spray great.

 

When I had my old 380 engine running on EFI, I could never get the idle very smooth at lower rpms. Somebody said that the spray pattern would cause the problem, and it is always the case with CIS conversions. I think it was because my engine had up to 36% leak-down in a test.

The injectors had 4 holes and pulsed twice per cycle. I've seen jetronic injector photos comparing air shrouding to non and the air shrouding looked pretty good.

If anyone has researched the newer direct injection systems, they are just astonishing. They have such precise metering control that they can mimic a smaller cylinder size by placing fuel just in the centre, so higher capacity engines can still get great economy. And as someone mentioned, they can fire multiple times to create different effects.

 

some direct injection engines are spray guided in which the injector is positioned near the spark plug or Flow guided; in which the cylinder shape is used to redirect the fuel spray towards the spark plugs.

I'm still learning about this in uni. I still have a loong way to go to fully understand it.