Mercedes KE-Jetronic - Holding pressures

This video has to teach you to make the difference between the fuel accumulator and the fuel pressure regulator. The fuel pressure regulator holds the working pressure so that the car can be driven as predicted and accelerate smoothly. The fuel accumulator has to hold the system pressure when the car is warm so that the car can be started easier WARM. Both of them when bad lead to pressure fall but how is it exactly? Find out in this video. HAPPY MERCEDESING!!!
link to my instagram profile
/ fix_your_mercedes
#fixyourmercedes##mercedeskejetronic##holdingpressure#
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"

[@bobexsus]

Congratulations on the 1000 your a big help to the classic Mercedes community

[@mercedeske]

Thanks a lot! Greetings

[@jeanjeanlebelge9263]

Bravo la j’ai compris la différence entre régulateur et accumulateur merci

[@mercedeske]

My pleasure!

[@jeanjeanlebelge9263]

@@mercedeske par contre le teste de maintien de la pression à 3 bar est seulement si mon distributeur ne perd pas d’essence par le piston car j’ai fait le test de pression et sa reste à 3 bar pendant 30 minute et après reste assez longtemps à 2 bar quand je pousse sur l’assiette à l’intérieur du débitmètre c’est tout mouillé et aussi quand je pousse sur l’assiette l’aiguille du manomètre monte de 2 bar

[@micheledirocco4994]

I'm happy for you and your channel and I wish you can have more and more subscribers! Ad maiora, Ivica!

[@mercedeske]

Grazie, bambino. Best wishes to you, too.

[@joer.6247]

Your videos helps me a lot! Thank you! 👍

[@mercedeske]

It was my pleasure 😊 ☺ 🙂 Glad to hear that 😀 🍀🍀🍀👋

[@johnnybravo6672]

Congratulations and good luck in your further work! Your Johnny Bravo always strong!

[@yaiselsalasar8171]

Gracias por la información, siempre eres de mucha ayuda,sigue adelante amigo.

[@mercedeske]

👍👍👍gfacias a ti tanbien

[@paulfester9652]

Congratulations Ivica !!!👏👏👏🍾🍾🍾. Here's 🥂 to the next 1000 subscribers 🤗🙏

[@mercedeske]

Thanks a lot 🙋🍀🍀🍀😃👋😉

[@paulfester9652]

If the fuel accumulater is good but the fuel pressure regulator is bad, will the holding pressure of +-3 bar still be kept when engine is off?

[@mercedeske]

@@paulfester9652 Yes

[@paulfester9652]

@@mercedeske So if the car does not hold the pressure @3 bar for 30 mins (engine off), it is definitely the accumulater that is faulty.

[@mercedeske]

Yes

[@AlexLopez-ow6gs]

congrats for 1000 ... please make a video about the inigter ignition module ground problems

[@mercedeske]

Thanks s lot I will try.

[@rioraton]

Hi again! I am still trying to sort out my 92 500sl COLD hard start issue. Your video here is the best explanation on youtube regard the differences between the FP regulator and the Fuel Accumulator. In my case I have no acceleration issues what so ever, cold or hot. I understand the fuel pump generates the fuel pressure and the Fuel pressure regulates this pressure. And, the fuel accumulator provides a certain pressure for a subsequent WARM start. Also, and not mentioned in your video, the Cold start jet adds extra gas for cold starts, 60 degrees and COLDER. You mention that the fuel accumulator must maintain 3 bars for subsequent WARM starts. Question: How long must the fuel accumulator maintain the 3 bars pressure?? CONSTANTLY after the car is shut off OR just for a specific period of time? PS if I pressurize my fuel system prior to cold start by turning the key on and off 2-3 times for a 3-5 seconds each PRIOR to a cold start it starts right up which tells me I am loosing fuel pressure over night some how? Also, my temperature where I live is NOT at or below 60 degrees. Could you let me know if the accumulator maintains constant pressure once the car is turned off. THANK YOU

[@mercedeske]

Greetings and thanks. Concerning your car specifically the residual pressure you get(engine off is something above 3 bar as I remember). Now, the answer to your question is YES, the fuel accumulator has to maintain that pressure for 30min. There are more places where the residual pressure can be lost, but the key component is the fuel accumulator as well as the pump if it's check valve is bad(as soon as you stall the engine the pressure drops to 0). Concerning your engine the cold start valve operates until 15°C, because that's the V8 engine. In the morning the engine is usually cold and the cold start valve helps the cold engine starts easier. Once the engine gets warmer, the accumulator is the one that should accumulate the pressure in the system and help warm engine start easier. That's it. What you do with the key you build pressure and that's why the car starts, that way you help the engine but this doesn't mean that it's a permanent solution. Greetings.

[@rioraton]

@@mercedeske thank you. Yes, you are correct this NOT a permanent solution. Yes, you are also correct more places where the pressure can be lost... injectors etc. If I might ask one more question... what happens to fuel pressure after 30 minutes of the car not running and assuming every thing else on the car is fine does the pressure go to zero or does it hold a 3 bars +/- ? thank you again!

[@mercedeske]

@@rioraton It stays 3 bar.

[@rioraton]

@@mercedeske Thank YOU! That my friend is what I need to know!

[@Mattospianos]

Thank you so much !!!! Unfortunately i've experiencing much difficulty in starting my W123 230E with warm motor....it's annoying

[@mercedeske]

You are welcome. If that is happening to you then check the fuel accumulator.

[@brianalcock]

Hi Did pressure test on both chambers today. On the lower I got a reading of 5 bars. When I opened the upper, I got a reading of 5.4 exactly. When I turned off the engine I got a reading of 2.7 bars. Did the test when the engine was cold. Yesterday I did the test on the lower chamber only and got a reading of 3 bars when I turned off engine. I presume all good ????? Think I'll move on to the Vacuum tests to sort my idle. Appreciate your great advise. Keep up the good work.

[@mercedeske]

Hi. Thanks. Everything is fine with the system. Search for vacuum leaks. Fingers crossed 🤞🏻 and Happy Mercedesing 😊

[@brianalcock]

Hi I have a 26OE 1989 (with no O2 Sensor) I have a constant issue with rough idle. I have check most things at this stage. Today I checked the fuel pressure at the lower chamber. When I started the engine I got an immediate 5 bars. I left the engine on until it got warm and it remained at 5 bars. When I turned off the engine it immediately read 3 bars. I returned 30 mins and it was still at 3 bars. 1) Should the fuel pressure be higher at idle? 2) Where should I look with those reading? 3) Any advise on what to do next.? Love the videos. Keep up the great work. Cheers

[@mercedeske]

Hi, and thanks. No, the pressure should not be higher on idle. Tell me did you get the differential pressure of 0.4bar? - Your situation looks like this - 5bar control pressure is normal for your car. As I have said in my previous video in English there are 2 pressures - the one when the engine is ON and when the engine is OFF. So, your car fulfills both values. As the engine is OFF it's normal for the pressure to drop at 3bar. That tells us(not US but YOU😄) that your pump is good, your fuel accumulator is good, pressure regulator as well and if you replaced the injectors then your mechanical part of the system is as it should be. As for the unsteady idle - if you replaced all the breather hoses and you still have unsteady idle then check the rubber boot(the rubber underneath the airflow sensor). If you get uneven idle again, then you will have to perform the fuel flow test out of the distributor simulating idle(sensor plate barely deflected) and you will have to compare the quantities you get per minute(5ml difference at most allowed). I know I made a "novel" out of this comment🤣😄🙂 but that's how it is. Fingers crossed 🤞🏻

[@brianalcock]

@@mercedeske Really appreciate your great knowledge and time about these engines. Will concentrate on .4 bar differential and breather hoses. Will report back. Thanks again.

[@r3FMusic]

Thanks..

[@wiktorgsxr]

👌

[@brianalcock]

Another great video. Would you know what is the correct thread size for the for adaptors going to the port at the upper and lower chambers. I presume it is a BSP thread. Trying to buy a tester kit with correct adaptors or I may make one myself. Well done again !!!!!!

[@mercedeske]

Hello, thanks. At the lower chamber 8×1 at the upper 10×1 I suppose.

[@elenakoskorou3612]

i love you.....tvx

[@mercedeske]

Thanks, glad to hear that from a female. I love you, too😊

[@runelarsen5769]

Yes, I like your videos. Is it the same when engine is cold or warm when testing Fuel Pressure Regulator?

[@mercedeske]

It's not. Test it when warm.

[@runelarsen5769]

@@mercedeske Thank you.

[@anthonyasmussen8732]

Denatha Primo

[@dikranberg7600]

Hi 😊👋

[@mrwilson7273]

Hey do you know why I’d have no fuel getting to the injectors? I have fuel getting to the distributor…

[@mercedeske]

Check at first the injectors. If they are okay, then check the fuel distributor if it sends fuel to the injectors. Engine OFF, unscrew the injectors and put the metal hoses in bottles. Make the fuel pump running constantly while the car is OFF and deflect fully the sensor plate. If you get no fuel out of all of them or out of some of them, you will have to rebuild the fuel distributor.

[@celts153]

Congrats ! Love your channel... Do you know if fuel regulator and fuel accumulator can be repaired ? They are very expensive parts tu buy for a simple membrane to change...

[@mercedeske]

Hi and thanks a lot. Unfortunately no, it's not possible. Both of them are sealed so that the replacement is the only option.

[@runelarsen5769]

Hi again. When I rev the engine like 7min:40sec in your video it is good. When I release the accelerator pedal the engine stops (stall) Any idea? Thanks.

[@mercedeske]

Hi. I'm glad you watch my videos. As for this issue - At first check how your sensor plate slides. Press the accelerator but in the engine bay not in the cabin. If the sensor plate returns too slow it can stall the engine. If that's okay, check your idle control valve if it operates when you apply a battery voltage(when the car is off). Clean it if you haven't. Check the values it gives you. Engine off ignition on, engine on ignition on and the voltage plus current(mAmps) on idle when warm. Write those values here in the comment.

[@runelarsen5769]

@@mercedeske Thank you. The idle control valve is new. Bought from Germany. Do you mean air flow sensor plate next to fuel distributor?

[@mercedeske]

@@runelarsen5769 Yes. It must slide easily without resistance, in fact without a slow back motion(when depressed).

[@runelarsen5769]

@@mercedeske I replaced the boot under the air flow sensor. There was a small crack. After that, hard to start and the sensor plate more stiff to push down. Not running engine.

[@michalmuszynski6942]

can pressure drop due to leaking plunger, if yes is there a way to fix it thank you

[@mercedeske]

It happens when the fuel filter is bad or when the fuel pressure regulator is bad but if the seal ring is leaking it has to be replaced.

[@michalmuszynski6942]

where is seal ring located, have regulated preasure at 6.1 bar try to kower it on fuel pressure regulator counter-clockwise how many turn to lower

[@mercedeske]

@@michalmuszynski6942 Why would you lower the pressure? Is the difference to small?

[@mercedeske]

@@michalmuszynski6942 The seal ring is located at the bottom of the plunger, the plunger rests on it. If you want to replace that ring you will have to take off the fuel distributor and to unscrew the sleeve(remember the gap between the nut and the sleeve) and as you take the sleeve off just remove the seal ring.

[@michalmuszynski6942]

@@mercedeske thank you for fast response

[@bozobeloica6346]

Da li mogu da dobijem neki vas kontakt. Potrebno mi je posto sam video da se razumete oko mercedesa i delova za njega. Moj otac ima problema oko jednog dela pa ako je moguce da vas kontaktiram za pomoć

[@mercedeske]

Pošaljite mi broj na [e-mail]

[@emiraceala2915]

Hello, where can I send you a video with the symptoms my car has? Do you have a mail adress?

[@mercedeske]

Yes [e-mail] Send me your phone number within

[@mrazekjan96]

Hello Ivica, should the pressure drop instanly when you turn off the engine, or gradualy? When I turn off the engine my pressure drops from 4,8 bar to 4,6 and slooowly climbes down to 3,2 in 30 minutes and yet i still have bad warm starts. Thank you!

[@mercedeske]

The pressure should drop instantly to 3.2bar. Have you replaced the injectors?

[@mrazekjan96]

Thank you!I see, no I havent I only changed the seals. Could the injectors cause the pressure to stay up?

[@mercedeske]

@@mrazekjan96 Maybe the hoses are clogged. Concerning the injectors they cause poor warm start. Replace them.

[@mrazekjan96]

Okay I will have to check that then! I have the injectors ordered so hope its the culprit. Also my engine is kindoff shaky, which could also be sign of bad injectors right?

[@mercedeske]

@@mrazekjan96 If you have good spark plugs, good cables, then either the injectors or the fuel distributor. In your case it can be the injectors.

[@stefangurtatowski3586]

Have to make pressure clock to observe

[@mercedeske]

Preassure gauge. You must have it. I must make a quick video for you to show you how to make the adapter easy and cheap.

[@stefangurtatowski3586]

@@mercedeske l measure fuel pressure and is 5,4 bar, 78 psi. My engine is M103, 300 12 valve 1992. What do you think about it?

[@mercedeske]

@@stefangurtatowski3586 As far as I know, these m103 engines must have working pressure of 5.7-5.9bar. I think it's too low. Measure the raw pressure(on the cold start valve), if you get over 6bar it's good, because then the working pressure can be increased.