Mercedes Ke-Jetronic - The duty cycle/how it's done

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2 жыл бұрын

#fixyourmercedes##mercedeskejetronic##thedutycycle#
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In this video how I explain about how you can do the duty cycle by measuring voltage and not the percentage and what is actually the duty cycle, how the engineers in Mercedes actually calculate the formula for the percentage. Can you actually use a common multimeter for calculating the duty cycle? That and much more watch just on the channel Fix your Mercedes.
What am I talking about?
My topic is the KE-Jetronic injection system which I try to demystify as much as I can.
For all of you to understand the system in brief - Developed in 1973 and being mounted into cars up to 1993 as it went in history. But why these to letters!?(KE) K(from German "kontinuierlich" meaning continuos, without interruption) the MECHANICAL injection system on which the fuel starts flowing from the fuel tank sucked by the FUEL PUMP and delivered to the FUEL DISTRIBUTOR which sends fuel to the INJECTORS while the majority of it flows through the FUEL PRESSURE REGULATOR through its return line back to the fuel tank again. The letter E(electronic) has to mark the electronic sensors (the developement starting from early eighties) which had to inform the ECU about the current state of the engine so that the ECU(Electronic Control Unit) then could create current signal in mAmp(miliampers) and send it to four crucial components for the system - the EHA(the electro-hydraulic actuator,a unit consisting of a magnet, an electromagnet and a baffle plate) which had to fine tune the engine in each of its phases, the ICV(the idle control valve), the unit which was predicted for the engines perfect idle, the X11(the diagnostic socket) where the duty cycle(the ideal mixture) was adjusted and the X11/4(the code reader) - the socket which from any codes were read if present using an OBD1 scanner.
An extraordinary injection system which could be fully repaired in your own garage using a multimeter and a pressure gauge only for its fine tuning, together with some common tools.
"Happy Mercedesing"

Пікірлер: 140

@bighilbili 2 жыл бұрын

I love how you take time to explain, especially in English,I am impressed from Oregon :)

@mercedeske 2 жыл бұрын

Thanks. I'm trying the best I can. Greetings from Serbia. Happy Mercedesing 😃

@treharris8482 Жыл бұрын

You have been such a big help with fixing my 190e 2.6 I couldn’t be more thankful for these videos

@mercedeske Жыл бұрын

Glad to hear that 😊 and to be of help. Happy Mercedesing 😃💪🏻🍀🍀🍀

@TRIUMPHINT 2 жыл бұрын

Thank you. You make a good job !

@mercedeske 2 жыл бұрын

My pleasure 😊 Happy Mercedesing 😃

@micheledirocco4994 Жыл бұрын

Sono onorato per questa menzione, Ivica! La W124 di mio padre è sempre stata la macchina dei viaggi di famiglia, sin da quando ero un bambino, e adesso anche grazie ai tuoi preziosissimi consigli è tornata a farsi ammirare per strada 😉

@mercedeske Жыл бұрын

Ciao caro mio Michelle. Sono contento che la Mercedes giri ancora bene per quanto riguarda l'iniezione, so quanto eri sconvolto mentre c'erano dei problemi, ma posso immaginare il sorriso sul tuo viso mentre la macchina ha ripreso a funzionare. Quanto a me, sono felice di aver guadagnato un vero amico come te. Ti auguro tanti tanti chilometri fortunati con la macchina. "Felice Merzando"

@cino4919 Жыл бұрын

Keep the car in the family.

@mercedeske Жыл бұрын

@@cino4919 Always!!!😃 You, too!

@knick187 Жыл бұрын

Thanks!

@mercedeske Жыл бұрын

Thank you. Glad if I could be of help. Happy Mercedesing Knick.🍀🍀🍀

@jancyran1832 2 жыл бұрын

Awesome videos, thanks to you i managed to understand a lot how the ke-jet works and how to troubleshoot it. Today I adjusted the potentiometer and the duty cycle and my 190e has never run smoother and it is more responsive to throttle. (The values before adjusting was 0.82v on the potentiometer and the duty cycle was almost 70%).

@mercedeske 2 жыл бұрын

Glad you made it. Happy Mercedesing 😃

@charlescarter2942 2 жыл бұрын

Hello Ivica, first of all thanks a lot for your channel and all the effort you're doing to demystify the KE Jetronic. I'm onto fixing/fine tuning my M102 W201 (w/o KAT) from 1989 and on the hood I do not have % on the sticker for CO adjustment. Do you know what 1,0 +- 0,5% CO means ? And how it should be measured with multimeter ?

@mercedeske 2 жыл бұрын

Hello and thanks. That means the allowed emission of toxic gases. In order to measure it you must have a gas analyzer which plenty of us DIY-ers don't. But with a multimeter which can measure duty cycle you can. Select the % option and your goal is to get 50% +/-5%

@fisehayehagos7714 2 жыл бұрын

Thanks 🙏🏽 thanks 🙏🏽 good job 👏🏽 🤝🙏🏽🙏🏽💪🏽

@mercedeske 2 жыл бұрын

You are welcome. Happy Mercedesing 😃

@fisehayehagos7714 2 жыл бұрын

Still I have problems The distributor is not passing fule

@mercedeske 2 жыл бұрын

Have you replaced the fuel filter? Have you checked the condition of your fuel tank and its filter(the strainer)? Then if you have no fuel low you will have to rebuild the fuel distributor.

@alaingillot4718 10 ай бұрын

On a cold car in open loop , you will read 50% fixed on/off ratio . In close loop , engine warm , that what you should be near . If you have an older analog voltmeter , in open loop , with voltmeter connected , set the voltage scale so the needle is somewhere on the scale , the value that you read does not mean anything ,make a note of that value, you are at a fixed 50 % .When the engine warm up , the oxy sensor now work , the needle will move somewhere up or down the scale , so with the 3 mm wrench adjust , so the needle goes back where it was in open loop , you are now again at 50% . the needle will oscillate near that value .

@mercedeske 10 ай бұрын

Exactly!

@meleajacobi1998 2 жыл бұрын

Have you said in which direction the screw has to be turned to get a richer mixture? Otherwise, excellent video as always!!!

@mercedeske 2 жыл бұрын

Clockwise - richer, counterclockwise - leaner

@meleajacobi1998 2 жыл бұрын

Okay thank you, i'm so glad that i found your Channel:)

@mercedeske 2 жыл бұрын

@@meleajacobi1998 Thanks a lot and Happy Mercedesing 😊

@orimorad3064 2 жыл бұрын

Hi, again thank you for another great video. Where can i find the specifications (EHA Current) for M104 and M119 engines? Working on 300SL and 500SL from 1990. Thank you!

@fisehayehagos7714 2 жыл бұрын

Please let me know if you have anything information about 560 sel Mercedes

@mercedeske 2 жыл бұрын

Hi and sorry for the delay, your comment was in spam. I have no idea why. As for the EHA I believe that for all the engines it's the same - on idle you will have to get the fluctuation between -3 and 0mAmps on idle and -5 to -7 at 2500RPM

@alexismontealegre1845 2 жыл бұрын

I love your videos man!. Thank you for all your help. I need a piece of advise from you from my situation if thats ok. On my x11 port 3 i get readings but when i put the black lead to port 2 the readings go away(duty cycle mode). Not sure why its happening. So i tried adjusting my lambda with just the red lead. I also noticed that the % goes down all the way to zero

@mercedeske 2 жыл бұрын

Hi. Thanks a lot. That was my case, too. The multimeter shows 48% and then falls rapidly to 0.9%. Try either to adjust the mixture (counterclockwise) but measure voltage as I explained. Is your lambda okay? It has to be replaced each 50k km(30k miles).

@alexismontealegre1845 2 жыл бұрын

@@mercedeske i am suspecting that my lambda probe/o2 sensor is my issue. I just bought the car recently without knowing that CIS even existed lol. So all these are new to me….. also im having multiple misfire it gets worse when everything gets warm i checked pretty much everything spark, vacuum leak and fuel. I pulled the spark plugs after few idle time and noticed some fuel on the spark plugs. Im guessing weak spark from ignition coil. Have you experience multiple misfires like mine?

@mercedeske 2 жыл бұрын

Have you replaced the injectors?

@alexismontealegre1845 2 жыл бұрын

@@mercedeske i have replaced them, also fuel pumps and fuel filter. I have multiple eha valves, ovp just for testing. Tested the resistance on CPS then they read somewhere around 800-900 ohms. Also the ignition coils are something like .5 ohms and 9k ohms. It has new spark plugs cap and rotors and spark plug wires.

@mercedeske 2 жыл бұрын

@@alexismontealegre1845 Did you glue the EZL with the paste? There is a special paste with which the EZL is glued to prevent the heating of the EZL.

@brianalcock 2 жыл бұрын

You are a fountain of knowledge. I have a 260E M103 and trying to identify low idle issue. You said in video that if you get constant 50%, there's a problem. Should the voltage fluctuate when doing the test? Cheers

@mercedeske 2 жыл бұрын

Hi, thanks. If you get a constant 50% that means that either lambda is defective or it is not ready to work. Usually, if there is a problem it should appear in a steady number, 60, 40, 20% for example. If the fluctuation starts between 50% everything is okay. You can do the same in voltage using the formula I gave, or even better - by measuring miliamps on the EHA. Cheers, best regards

@brianalcock 2 жыл бұрын

Thank you for your reply. Trying to figure out this problem for the last 12 months. When cold it takes a few seconds to start. When the car heats up, it hovers on idle at approx 500 rpm. Sometimes in traffic it would stall and not start again. If I wait awhile it will start again. My 260e has 9 pin circular diagnostic connector but it has no lambda sensor or catalytic converter. Did another Voltage check today on Pins 2 & 3. It read a constant 7.05volts. Also did a Duty Cycle Test on Pins 2 & 3 but also remains constant at 50.6% and 97.61 Hz. There is no fluctuations. Any advise ??? Your videos are excellent. Keep up the great work. Cheers

@mercedeske 2 жыл бұрын

@@brianalcock Hello and thanks. If your percentage remains on steady 50% then your mixture is excellent. Did you check the potentiometer? Do you get steady 0.7V on idle when the car is warm? If yes, then check the idle control valve?

@brianalcock 2 жыл бұрын

Took it for a 5 mile drive before I checked the duty cycle. On idle it remains at 7 volts. I also checked the potentiometer and that appears to be doing its Job. Will check and clean out ICV and report back. Cheers

@brianalcock 2 жыл бұрын

Hi. Managed to take out and inspect ICV. Appeared OK. Tested it for resistance and it read 00 ohms ??? Soaked it in brake cleaner overnight and reinstalled it. Reconnected voltage connector and put key in start position. I could physically see the circular valve moving freely. Went for drive but still have low idle and slight stutter. Do you think it may still be an issue with the ICV because of the zero ohms reading?????? Really appreciate your time and great advise. Cheers

@knick187 Жыл бұрын

Is the fluctuations rite for a 119 i mean the one you are giving in this video

@mercedeske Жыл бұрын

Yes, it is.

@ell7851 Жыл бұрын

Hello, thanks for your helpful videos. I’m in trouble with my w124 200. I made de duty cicle diagnosis with a multimeter and a socket. I shows is a lambda faults (99,9 %) i replace it but I have the same results.

@mercedeske Жыл бұрын

Hello and thanks for the comment and your compliments. In order to help you I must know if you have been readjusting the CO-screw, if your car has been manufactured before or after september 89. For now the only thing I can tell is to remove the signal wire from the lambda when the car is at the operating temperature. If you get 50% then you have an interruption in the wires. Then check for continuity the connector for your lambda and the 8th pin of the ECU connector. If you don't get a beeping sound then there is an interruption in the wires. That much I can say from this aspect.

@ell7851 Жыл бұрын

@@mercedeske my car is a 92 model, I’ve tried to adjust the co screw, but nothing change, it seems like I don’t have signal on x11 socket

@mercedeske Жыл бұрын

@@ell7851 Check for it. 100% says NO VOLTAGE OR GROUND ON X11, SHORT CIRCUIT OR LINE INTERRUPTION BETWEEN THE DIAGNOSTIC SOCKET AND THE ECU, LAMBDA DEFECTIVE, NO VOLTAGE OR GROUND ON ECU - OVP DEFECTIVE(check the contact 87E on the OVP), MIXTURE TOO LEAN - LAMBDA DEFECTIVE, SHORT CIRCUIT ON GROUND! That's what you have to check, everything I have mentioned.

@ell7851 Жыл бұрын

@@mercedeske thanks

@ell7851 Жыл бұрын

😢hi man. I’ve tried many things: 1) i have voltage between 2 and 3 ok socket ( 2,45 V Dc at idle) 2) i have ground on ecu 3) lambda is new 4) new odp relè But nothing change😢 can i send a video on your mail?

@jangyoseong4605 2 жыл бұрын

hello. I bought a used part to replace the throttle body, but the part has the hole entrance that is adjusted with a hex wrench blocked with something like silicone. Is it the cap that originally blocks the entrance to the hall? What should I do if I think I will have to remove the cap to steer it with a hex wrench? Seek advice on how to solve it.

@mercedeske 2 жыл бұрын

Hello. Don't touch that screw. You will never manage to make the tps working properly.

@jangyoseong4605 2 жыл бұрын

@@mercedeske thank you I am not trying to manipulate the screw, I am asking if it is possible to remove the cap that blocks the entrance to the screw adjustment hole, and if it is possible to remove the cap, I am asking how to remove it.

@mercedeske 2 жыл бұрын

Mine was off, so it is possible but you really don't have to do it.😀

@muhammadzeerak7631 2 жыл бұрын

What % should the car be at for the system to work properly

@mercedeske 2 жыл бұрын

50% +/-5%(the higher the % the leaner the mixture and vice-versa)

@universalvideos7553 9 ай бұрын

Mercedes 320e w124 W124. 023

@Takumo1 11 ай бұрын

Hi i have w201 102.962 RUF from 1986 with O2 sensor. Multimeter is showing 50% duty when ignition is on even if the throttle valve is fully open (should be 20% duty, am i right?). When engine works duty is also 50%. I would say that there is problem with O2 sensor but why it doesnt shows throttle valve open?

@mercedeske 11 ай бұрын

Hi.The % on ignition ON has to be 70% and after starting the car it should rise to 50. If you have never replaced the lambda, do it.

@Takumo1 11 ай бұрын

@@mercedeske Thank you. I know it but i'm asking is this normal symptoms of damaged lambda or its causing by other sensors?

@davidfenton5955 2 жыл бұрын

Hi Ivica. If the car does not have a Lambda Probe do you still set the Duty Cycle in the same way?

@mercedeske 2 жыл бұрын

Either with % steady 50% reading or measuring current on the EHA. The same procedure. The more the mAmps go in negative, the richer the mixture and vice-versa. On idle you have to reach 0 mAmps. As for 2000rpm for m102 engines it says 3-5mAmps, as for m103 engines -3mAmps as far as I know. Now, there should be compromise between the % and mAmps. Either leaner mixture- the car runs a bit sluggish(ecology matter😃) or you want the mAmps and the mixture a bit richer(the car runs better but it will have a bit higher consumption). (The underline on 3 has to show NEGATIVE 3)😃

@davidfenton5955 2 жыл бұрын

@@mercedeske Thanks Ivica. Always appreciate your knowledge. I’ve ordered a fuel pressure gauge, I’m really looking forward to using it so I can get some facts, and hopefully be another step forward to having my 260SE running sweet as a nut. All thanks to you and your invaluable videos. Speak soon, and Merry Christmas.

@mercedeske 2 жыл бұрын

@@davidfenton5955 Thanks for everything and merry Christmas 🎅 🎄 to you as well.

@knick187 Жыл бұрын

So what would it be for 119 engine for idle an do u adjust the c/o with the fully of or on second turn?

@mercedeske Жыл бұрын

As soon as you have a brand new lambda and the potentiometer you should have a good mixture adjustment under the condition that no obe has been messing up with the mixture screw.

@knick187 Жыл бұрын

Someone has messed the mixture up soon as I find fuel pump relay I will do what u have put up for duty cycle

@knick187 Жыл бұрын

The mixture screw has been messed with when adjusting mixture screws the car is running rite? Or in second position I have done the formula with x11 with the key turnt to second position and battery with car of my nbr was 35 to rich so from here do I Turn mixture screw with Key in second position till I get to 50 Or Have car running an make adjustment till I get 50 bearing in mind waiting 10 seconds b4 every adjustment Plzz plzz help I'm going crazy 🤪

@mercedeske Жыл бұрын

@@knick187 🙂Do it like this. Get the car to the operating temperature. Once you do, measure voltage - pin 2 ground, pin 3 positive. The goal is to achieve the fluctuation 6.6-7.3V. Then you will have a perfect running engine.😉😊👍🏻🍀

@knick187 Жыл бұрын

@Fix your Mercedes thank you for reply my so called mechanic put in new fuel pumps an filter just last year ...but the cover for it was never put back or lost ? Could that be a big factor in why pumps gave out so early ?

@juhis233 2 жыл бұрын

Awesome work again! I dont't get any voltage on my x11 pin 3, buy for example i get voltage on pin 2.. What could be the problem?

@mercedeske 2 жыл бұрын

Thanks. Number 2 is ground. Number 3 for duty cycle. Do you have just a hole on pin 3 or it's connected? And how does the car behave?

@juhis233 2 жыл бұрын

@@mercedeske It looks like it is connected like all the other pins. The car has pretty high fuel consumption and also it feels like the car is not getting the right mixture when accelerating from 0km/h when the car is warm. It kind of jerks when accelerating

@mercedeske 2 жыл бұрын

@@juhis233 If you have lambda and it's never been replaced, then replace it. In order to do the duty cycle your lambda and potentiometer must be functional as well as the eha.

@juhis233 2 жыл бұрын

@@mercedeske I recently replaced the lamda with bosch oem part. It didn't have amy effect on performance etc

@mercedeske 2 жыл бұрын

Try it like this. As the car is on 80C hook up the multimeter on the eha(if you don't get the reading for the first time then replace the leads, the polarity changes always on the eha) you will have to read between-3 and 0 mAmps.

@alfa9703 19 күн бұрын

Helo. My duty cycle always around 70% no matter what i do i dont get 50%when i start cold.so far i changed o2,poti,fuel pump,fuel filter,ovp,cts,ecm. What else could this be ?

@mercedeske 7 күн бұрын

Try testing the speed sensor!

@louis525d7 Жыл бұрын

Hi, does it work if my car has no o2 sensor? 190e m102 EU spec from 1990

@mercedeske Жыл бұрын

Hi. Yes, it does, you just have to get steady 50% So, no ups and downs, just steady 50%

@louis525d7 Жыл бұрын

@@mercedeske Okay im gonna do that, I changed the potentiometer and eha is working well but the sparksplugs are still looking whitey. I hope setting the co screw will be the solution. Thanks for your response keep doing it man your the best

@mercedeske Жыл бұрын

@@louis525d7 Thanks. You can measure the mixture on the EHA. Your target is 0mA when the engine is warm, -2 if you want a richer mixture. Good luck!

@brutale88888 2 жыл бұрын

Hi, I have a problem with the w201 190 1.8. When I slow down and stop the car, the speed drops and the engine shuts down. I would like you to tell me what to watch out for. Please help me. Thanks.

@mercedeske 2 жыл бұрын

Hi, many factors can have influence here - the potentiometer, the TPS, the microswitch, the lambda if you have one and the last but not least - the ICV! You will have to check all these if they are as they are supposed to be!

@brutale88888 2 жыл бұрын

@@mercedeske there is a case that the idle valve is responsible???

@mercedeske 2 жыл бұрын

It could be. The ICV has to bypass the air to the cylinders. If it sticks and won't open enough then the car stalls.

@alexismontealegre1845 2 жыл бұрын

We have to us DC right?

@mercedeske 2 жыл бұрын

Right

@universalvideos7553 9 ай бұрын

Hello Mr Ivica my car euro spec has no O2 sensor is it possible to do percentage test on port 1 and port 2... I don't have port 3

@mercedeske 9 ай бұрын

Hello. No it's not possible on those ports. Btw. something here is not right. Do you have a W124 230E or a W124 320E, there is a HUUUGE difference there!? Because W124.023 is a four cylinder 2.3l engine, not a 3.2l six cylinder engine!

@universalvideos7553 9 ай бұрын

@@mercedeske thanks for your reply

@universalvideos7553 9 ай бұрын

@@mercedeske yes Mr Ivica its 230E 2.3L engine... My problem is running very rich the mechanic adjust EHA pressure difference 0.3 bar to make it leaner but Milliampere on EHA is about -4

@universalvideos7553 9 ай бұрын

@@mercedeske today i will check duty cycle as you advice in video duty cycle on EHA..

@universalvideos7553 9 ай бұрын

Hello Mr Ivica.. I check duty cycle pressure difference 0.4 bar EHA screw adjusted at 6.6 mils engine temperature at 80 degrees EHA shows -4 Milliampere rich mixture at idle is there anyway to make it leaner

@cristo_9542 Жыл бұрын

I got 10, 30V and 14V batteries. What is next?

@georgesand4629 2 жыл бұрын

I’ve got a 86 420sel. I put red lead on #3 port and it has a reading but when I put black on #2 port it doesn’t work. This is on the x11 port.

@mercedeske 2 жыл бұрын

Which readings di you get?

@georgesand4629 2 жыл бұрын

I decided to use a regular multimeter and did a static test with engine cold. I got 12V for the battery and 3.58 for pin 3 on X-11. This is for 1986 420 sel.

@mercedeske 2 жыл бұрын

You must perform the test when the engine is warm. If you got steady 3.58V then that's not good.

@georgesand4629 2 жыл бұрын

Okay I got a multimeter with duty cycle function. I drove it for 10mins and did the static test with left vac hose plugged it was 69.8%. I started the car and it was going all over from 53-66%. I turned the co screw cw to lower the duty cycle but it went higher. I moved it more until the engine started to not run as smooth. I turned it ccw until it smoothed out and ran better. The duty cycle went down. I turned it further to but it didn’t run as smooth so I left it where its at. My original problem was a shaky engine idle but the car started and ran good just the idle was the issue. I messed with the co screw without knowing about the duty cycle and the next day the engine had a hard start when cold. I checked for vac leak and found one at the AFM so I fixed it. I also put a new o2 sensor. That fixed the shaky idle but now I’ve got cold start issues and a duty cycle that is all over the place. I checked with a regular multimeter and the battery was 13.98 volts and 12.98 at pin3 . I did a hot start after the duty cycle adjustments and it started fine with a hot start. The idle is smooth but we’ll see if I have cold starting issues again.

@georgesand4629 2 жыл бұрын

I made a video of my duty cycle test if you’d like to see it. It’s on my KZfaq. Thanks

@milosvucic6962 2 жыл бұрын

Pozdrav druze, vidim da znas sve o k glavi, jel imas ti radionicu ili ako znas nekog majstora da mi preporucis? Hvala

@mercedeske 2 жыл бұрын

Šta te muči konkretno?

@milosvucic6962 2 жыл бұрын

Tesko pali, i kad upali ne radi ravnomerno na leru.

@mercedeske 2 жыл бұрын

@@milosvucic6962 Jel si menjao potenciometar, dizne?

@milosvucic6962 2 жыл бұрын

@@mercedeske Nisam jos nista dirao, nece majstori ni da pogledaju kad cuju da ima k glavu 😆 moracu izgleda sam da ga cackam cim malo otopli.

@mercedeske 2 жыл бұрын

@@milosvucic6962 Pa, to. Znam. Prati moje videe, imaš na srpskom sve što ti treba, popravićeš kola sam, garant!

@salehfiras943 2 жыл бұрын

What if my multimeter is showing me 99.97% on duty cycle no matter if i turn the hex screw ,i have a brand new potentiometer,o2 senzor and eha and i changed 3 ecu same result...

@mercedeske 2 жыл бұрын

Either the multimeter is bad(I had that problem, I couldn't do it in %) or there is a code stored in the ECU(most likely the O2 sensor). Although you replaced the O2 sensor, the ECU gets the information it is bad. If this is the case you will have to erase the code.

@salehfiras943 2 жыл бұрын

@@mercedeske how do i erase the cod?

@mercedeske 2 жыл бұрын

There is a rectangular diagnostic socket by the battery. Plug in a wire in the contacts 1&3 for about five seconds and take the wire out. If you get a single beat, everything is okay. If you hear more of them, then text me.

@salehfiras943 2 жыл бұрын

I put the jump wire from 1-3 but i didnt hear any beat shouldn't i use the specific diagnostic tool with the light?

@mercedeske 2 жыл бұрын

@@salehfiras943 You can try with the obd1 scanner. It can be found on ebay