1989 560SEC, 1989 560SEL, 1995 E420
I'm getting closer on mine, H.D.
So, What readings would be valid for diagnostics? And why are the other readings worthless? I am sure you've explained this but.... Every time I think I understand this, I get more info and more confused! Before I buy more parts and switch them out, even though the adjustment tower has been fiddled with, you are saying that it is still a very valid diagnostic tool, but limited...? I saw where you said the duty cycle should be run after changing out anything involved with the fuel system... would that give a new starting point per se, and then become the 'base line' measurement for further duty cycle measurements along the way? I'm sort of confused... can the duty cycle ever become valid once again for ALL measurements?With the adjustment tower having been tampered with, the duty cycle readings while the engine is running are worthless with regard to their diagnostic value, of course … but not the other readings !
Many a MB mechanic said exactly the same thing in the 1980‘s. … LOL ... Let‘s go through this step by step, covering all your questions. I‘ll probably become quite busy with other things in the upcoming days, but right now I still have some time for that.Every time I think I understand this, I get more info and more confused!
Vp6 should be about the same as the battery voltage … both with “ignition on / engine off“ and with the “warm engine running“.So, What readings would be valid for diagnostics?
As I said in post #80, these readings (4, 5 & 6) are in your case worthless “with regard to their diagnostic value“ … because the Lambda adjustment screw has been messed with !And why are the other readings worthless? I am sure you've explained this but ...
The above listed duty cycle measurements 1, 2 & 3 (with ‘ignition on / engine off‘) and their static readings always provide valuable diagnostic information … no matter whether the adjustment tower has been fiddled with or not.... even though the adjustment tower has been fiddled with, you are saying that it is still a very valid diagnostic tool, but limited...?
I said … for instance, in post #39 of my Lambda control thread … that the duty cycle should be readjusted (not “run“!) via adjustment screw as “the last thing to do after fixing all causes for its deviation“.I saw where you said the duty cycle should be run after changing out anything involved with the fuel system.
Yes it can … as you can deduce from the above quote from post #39 of my Lambda control thread. … First check and, if necessary, fix everything that has an effect on the fuel combustion. That includes things beyond the injection system, of course. After that has been thoroughly done, adjust the fluctuating duty cycle via adjustment tower while the warm engine is running at idle to a value close to 50% (EHA current fluctuating around zero mA). Then you have a proper basis for reliable complete future duty cycle tests again.... can the duty cycle ever become valid once again for ALL measurements?
Thanks Randtor. ... Last year I told an ex-colleage of mine that I‘m trying to explain the KE-Jetronic in a car forum. … His only reaction was: “Auwei!“ (“Oh dear!“) … LOLOnce again H.D., kudos to you for taking your invaluable time to go through all of this.
Haha … probably my English gives me away, right !? … I reside in Germany.I'm fairly certain you do not reside on this side of the pond(USA), but if you did I might have paid you a visit just to shake your hand and buy you a drink!
With that instrument I can check a number of things, not only the duty cycle. It enables me to track down culprits within two or three minutes, which I sometimes see taking weeks or months in troubleshooting threads here at Benzworld.I wish I had the knowledge to build that 'duty cycle instrument' ...
… I generally prefer testing & diagnosing over throwing parts at problems. Purchasing parts that do not replace culprits does not contribute to my enjoyment.In the meantime, I plan on doing everything you have outlined before I purchase any more parts
Take your time Randtor … and don‘t think of the duty cycle test as being difficult. The most difficult part is the general dealing with a digital multimeter. For the two Vp6 measurements and the six Vp3 measurements just follow the procedures in post #83 ... and don‘t care about “pulling off the vacuum line between the throttle valve and the regeneration valve of the fuel evaporation system at the regeneration valve and blocking it“ this time.I will not be able to get to the testing procedure until the weekend, at the earliest, but no later than next week. I can use the time between to study the procedure more and get a good grasp on what I will need to do.
I actually prefer not to become too active in this forum before the technicians will have recovered the features that the forum had before August 20. Administrators told me they are working on it. … But questions regarding the test device you can post in that thread. I think that makes more sense than posting them here in this thread. You can also post questions about it via email, if you like.In regards to your measuring device, I am in contact with my electrical engineer friend and he has done a preliminary overview. He already asked me some questions, but they are above my pay grade lol! If he has further questions would it be alright to post them here, or would you prefer I post them on this thread :
I‘d like to introduce a simple self-built on-board test device that provides diagnostic information (mainly) about the KE-Jetronic fuel injection system anytime … while driving or parking. … Makes detecting or narrowing down problems a lot easier, especially if they occur intermittently. …...www.benzworld.org
I don‘t know what you mean by “can we duty cycle“ and by “KE brethren“. I assume that by “CIS K system“ you mean the “K-Jetronic“. … This thread is about the KE-Jetronic, which is so different from the K-Jetronic that, in order to avoid unnecessary confusion, details about the former should, IMHO, not be discussed in a thread about the latter and vice versa.can we duty cycle a CIS K system or is that just for the KE brethren