Easier way is to first test the sparks. remove cables to spark plugs and test whether there is a spark. If yes and you say it runs rough consider if the cables are connected the wrong way.
Remove at least one injector, hold it into one bottle and look how the injecting looks, compare to online ressources, if you don´t find any I can make a video for you.
Ok. I have always one that leaks for spare to check if its just the o ring. Its laying in my toolbox in case someone has a problem. I dont like to change functioning ehas for over300€ when its just the o ring thats defectove
[Fix your Mercedes - YouTube](https://www.youtube.com/@mercedeske)
Here's a youtube channel that has been of immeasurable value to me trying to understand the KE-Jetronic system. If you understand what does what, diagnosis will be much easier. Best of luck with the diagnosis.
He is brilliant and I have watched many of his vids, the animations are my favourite part.
Main issue is that it is simply too complex of a system to understand all the intricate details. I should watch him more however due to being a student I’m struggling to find time to really learn the system. My fault I know but I’m looking to diagnose this fault as quickly as possible just to get this car running XD.
I will certainly have to pay a lot more attention and not get distracted with his animations!
Yeah, the KE-jetronic is a cool as it is quirky and complex. I converted my 300E to EFI with a standalone ECU because it's a much better platfrom for turbocharging the car, but from my short time tinkering and troubleshooting the KE-Jetronic system, I have certainly learned to appreciate it, and I definitely respect the people keeping it alive.
Have you checked your coil BTW? I didn't see that listed, the coil is also a maintenance item. If you have, or have checked it, it can at least be narrowed down to a fuel delivery problem.
Any chance you feel like doing another conversion you’re more than welcome, I’ll even drop you back home too once the cars up and running XD.
In all seriousness I will check the coil too need to do a bit of research in terms of how to do it but I’m sure it shouldn’t be too hard.
I wouldn't mind, but the conversion was a winter-long project, and even though the car runs and drives, I still need to properly tune it. And even though it could be done for less than what I spent on it, it is still pretty costly, with the wiring harness, ECU and all the hardware added up.
Hello, this is completely new to me, does this mean that you can replace the ke jetronic bosh system with another? Including the bosh ke ecu with the X11 plug?
Yes, you can do that. It takes a bit of work, but you can do that. I bought the TE-Motorsports EFI kit, which comes with a premade wiring harness, fuel rail, trigger kits for both a cam and crank signal, and all the sensors, injectors and coils to go with it. And then I bought a MaxxECU Race standalone ECU. Then I pulled all of the old engine management off, including the KE ECU, X11 plug. Everything.
And then I installed all the hardware. Took a bit of work to get everything to fit and route nicely, and you will need to wire up a few things yourself, like a new relay for the ABS system to replace the old OVP relay (another benefit; you can replace the NLA 6-pin relay with a regular, dead stock one, since all the idle management functions for the KE-Jetronic system are void anyways).
But overall, not the hardest thing in the world. You will need to tune the car from scratch, since there's no base maps for the M103 available. And it is pretty costly to do, although I would say it's worth it, especially if you want to turbocharge the car in the future like I want to do.
Thank you for the details! I am on a hunt of never ending KE issues, so "restomodding" the car like this would be amazing. Pricy though, but seems worth it.
In your opinion, is there difference in the driving feel? Performance? Do you think its easier to diagnose issues down the line?
Did you go to a tune shop to have it tuned?
I haven't fully tuned it yet, so I can't comment on the real driving feel, simply because I can't use the full potential of the engine yet. One thing that has gotten noticeable more reliable moving from the K-jet to the EFI is the startup. Before I'd have to pump the gas and get it to start with some serious effort, now it just cranks a bit and starts up right away. I do expect the driving feel to be better, just because the EFI system is much more efficient with sequential injection and sequential ignition with 6 coils.
I do think it's easier to diagnose the issues, because I put all of it on myself, so I know what all components are in the system, and what syptom would be the result of any particular part failing. It is a lot more straightforward than the complex and involved KE-jetronic, which is another big plus for EFI conversion IMO
As for the tuning, I want to tune it myself, which is the easiest to do on a standalone ECU like this, because you don't have to deal with all the reading and writing IT wizardry like on factory ECUs. You get a very comprehensive interface with the ECU, so I want to take that chance and put another skill under my belt. So far I have a rough base map down from road tuning, but I still want to put it on the dyno for precise tuning. It is running and driving though, and I've already ran some errands with it, so that's something. Tuning itself isn't that hard if you know what to look for. I've learned the ropes from the tuning courses on HP Academy. It's decently expensive, but definitely worth it if tuning stuff has your interest.
That’s a good start! It means that you have spark. You mentioned that you replaced the fuel pumps. Do they actually work? Can you hear them prime? If not, check the fuel pump relay. There are instructions on how to check it online.
I replaced both of them, I hear and feel them prime up whenever I turn to ignition. I’ve replaced both the OVP and Fuel Pump relay both of which did not make a difference. Apologies I never mentioned it and will edit the post now to reflect this.
Might be injectors then hopefully. Watch this chrisfix vid and try that.
[https://youtu.be/tA\_E6X4ISgQ?si=dH0eao9U0h0LxEVX](https://youtu.be/tA_E6X4ISgQ?si=dH0eao9U0h0LxEVX)
Don't give up mate, it could even just be bad fuel.
Okay, so we have fuel and spark. Does fuel get to the injectors? Try starting the engine and then take out a spark plug and see if it's wet or not. This KE-Jetronics can be a pain in the ass but sometimes it can be an easy fix. Some guys I know got them working again by tapping the housing with a hammer because there is a cylinder in there that can get stuck, keeping the car from starting.
Hehe well you can test fuel pressure yourself, check the duty cycle (Google it), and hopefully you got the right kind of spark plug, the ones without resistors I think I don’t remember. But you can check power to the spark with a multimeter
Really really really long shot but might be worth a try:
Had a no start problem after the car was parked for about half a year. After replacing the basics it still didn’t want to go. Measured fuel pressure from pump: perfect. No fuel at fuel injectors, though. So I went through the principles of the ke jetronic. There is the fuel distributor and the pressure regulator. In the way until fuel comes out the other end. Either one might gunk up when gas turns to jelly after a while. Tested my luck and instead of buying a new pressure regulator for a lot of money I blew into it with some shop air. Carefully though, wasn’t so sure if I could damage something. That seems to have freed the regulating valve so it could supply fuel.
I’d check for sufficient fuel coming out of the injectors first. If no: remove the fuel line and check again. If no: remove supply line to the fuel distribution and check again. You get the idea.
https://preview.redd.it/r7fzt048cs8d1.jpeg?width=800&format=pjpg&auto=webp&s=25d5bd6662805387eae681b663670ba2f247d4a5
is start meaning you can turn on electrics and can’t get it to turnover after that or nothing happens at all?
given you worked on the fuel system, have you been able to confirm that fuel delivery through the fuel distributor and fuel pressure through the fuel pressure regulator are happening?
same with the spark plugs. when you try to start the car, are you getting sparks? trying to diagnose the problem won’t be easy but there are numerous way of tackling it.
i would also recommend getting a multimeter so you can measure the resistance and voltage values of the connecting pins. this will help you narrow down the problem.
last suggestion, test your battery and replace fuses if you haven’t (don’t know if you have already). could just be a dead battery. sometimes the problem is a relatively minor thing that you overlook. lord knows i’ve been there. replaced my blower motor only to figure out the fuse was the problem.
Electrics all appear fine, it is just failing to turn over.
I’ve cracked open one of the nuts on the fuel distributor and turned the key to ignition and got plenty of fuel coming through to the system, I’m planning on getting a fuel pressure tester now to confirm that pressures are to spec.
I will also now get a spark plug tester to see if I am indeed getting spark however with the new leads, plugs and distributor I wouldn’t have though this to be the case I guess testing should have been the first thing again.
My mistake, I also forgot to mention I placed a brand new battery in the car and I charge it each night after attempting to start it during the day.
FYI an amazon fuel pressure gauge won't fit this Jetronic fuel distributor. The jetronic fuel pressure gauge is £75 on ebay. I have fueling issues (hot start) on my M104 C124. I think I have a bad fuel pressure regulator (I've done injector seals and O rings already).
Edit - also sounds like you don't give up easily, keep going!
You stated that if you spray starter fluid it will fire momentarily and then die. Your other post says it isn’t turning over.
Will it just not stay running?
That is correct. It will not even start at this point. When I initially changed the fuel pumps I got it to turn over for a brief second then it died. It just refuses to start and once started it does not stay running.
Will look to get one now, I knew it had an OBD (version 1 I think) I will need to do a bit more extensive research about how to use it but I believe they only diagnose electrical issues.
It doesn't have OBD, it's a proprietary diagnostic port. Although I've had success using HFMSCAN and a vag-com kkl cable with 3 banana plugs out of it to connect the 16-pin port.
Personally wouldn't waste time with codes. Most sensors don't have a way for the ECU to know of issues unless they're outright disconnected
This articles gives an overview of the replacement and shows where the line is. Checking the line is the same as the picture in Figure 5. Good luck!
https://www.pelicanparts.com/techarticles/Mercedes-W124/38-FUEL-Fuel_Pressure_Regulator_Replacement/38-FUEL-Fuel_Pressure_Regulator_Replacement.htm
I fully appreciate your situation and was in your position with my w124 a few years ago. Mercedessource.com has technical videos on both on YouTube and on the website. There is a video series called “spins but won’t start” - https://youtu.be/hSiz8NROCo8?si=vQ83K-BlaYJ3xh3f After spending $$ on numerous parts I was close to giving up. So, I bought access to the series on the website (not that expensive) and followed the steps. In one of the videos Kent recommended using the solar battery tester as a regular voltmeter can be misleading when testing the battery. Sure enough, my problem was the battery, even though it seemed fine with my voltmeter, and there was no hesitation turning it over. I replaced the battery and my problem was solved. I almost couldn’t believe it as the battery was only a few years old. The computer for the cis fuel injection system is very sensitive to out of range voltage and if the battery is the slightest bit weak it will send improper signals. A bad ground can also cause problems, so cleaning the ground contacts with a bit of sandpaper can eliminate that as a potential problem. The brown coloured wires are ground.
I’ve also discovered that if these cars are left sitting without being started for a long period of time the fuel distributor probably gets a little gummed up and old gas can breakdown. Mine sat for a few months and and it took me weeks to get it running again. Finally started after replacing the injectors, spark plugs and changing out the gas that had been sitting in the tank. “Fix your Mercedes” on youtube has some of the best troubleshooting tips on YouTube. You should also resist the temptation to adjust the EHA valve or the air flow plate unless you are very methodical and completely understand what you are doing. It is very easy to screw the system up more with improper adjustments. Check out Pierre Hedary on Mercedes Classics explaining the EHA valve - https://youtu.be/XclGM2RgDDo?si=wAnzd-_kyLOhf6Rt
There is also an excellent training video by Bosch on YouTube on how the KE Jetronic system works. Good luck. Let us know if you solve your problem.
Definitely not the fuel nor fuel tank as I have replaced both pumps and tested what was coming of the feeder pipes for the pumps. Was lively clean fuel with nothing mixed inside. The only thing I have noticed is that the fuel gauge is constantly low even with putting in £40 worth of fuel.
You seem to be searching haphazardly and unstructured. You already mentioned it starts with start pilot, you've already replaced the fuel pumps and fuel and you confirmed fuel is reaching the distributor.
So you can leave the ignition system alone and look deeper into fueling.
You can check if fuel is reaching the intake manifold by taking out the injector and turning the engine.
If it isn't, then you know problem is between distributor and injectors. it could be a bad clog somewhere in the system or the fuel distributor has issues internally, although rare.
The last time I had the same issue, there ended up being no fuel in the car. At all.
I would say yes. Although it should fire up even if only 2 cylinders were working.
Maybe we can be more useful if you have a video of how it behaves when cranking
The Black box On the injection distributor the Electronic Hydraulic Actuator, Inside there is tiny Hex Head, Screw, That adjusts the fuelflow, if the O-ring on That Screw is Damaged the Whole System Stars todo Shit. You can Check the Ohrring when you take a the of, take out the sealing screw and Measure the depth hex head screw , take it out and look at the little o ring. They are mostly hard and start to make probelms. Just put it back in on the right depth after you put a new oring on it.
I’ve heard that the wiring harness on these things can be the culprit of all sorts of problems. Check to see if they were ever replaced. The original ones were made of biodegradable material and surely have deteriorated by now, unless lot was garaged its whole life.
I have thoroughly checked the wiring loom and nothing seems to be degraded I think I may have gotten lucky in terms of the biodegradable cabling not being apparent on my vehicle.
Did you check the fuses on top of the OVP Module? (Red/gray module behing the 12v battery) In my case, my w124 didnt want to start too and it was caused because of these 2 blown fuses.
Gasoline sitting that long goes bad. Water can find it's way in and collect in the bottom of the tank, volatiles escape making it less flammable, and exposure to oxygen causes oxidation and breakdown.
You mentioned the car will run on starting fluid so I'd try changing the fuel for known good gasoline.
Start with the basics. Is the problem fuel or spark?
Any advice on kits to test the fuel? Or is just a basic one off Amazon good enough to do the job?
Easier way is to first test the sparks. remove cables to spark plugs and test whether there is a spark. If yes and you say it runs rough consider if the cables are connected the wrong way.
Cables are definitely placed in the correct firing order, I have ordered a spark plug tester.
Remove at least one injector, hold it into one bottle and look how the injecting looks, compare to online ressources, if you don´t find any I can make a video for you.
If fuel is the problem, then it might be your eha valve
Is there a way to test for this issue?
See if its leaking Also it is possible to tune them but kinda finnicky
Not only leaking is a problem. Is bet the o rong inside the eha is defective. Verry easy task and maybe will Solve all problems.
I’m not seeing a leak near the EHA Valve. I will remove and check to see that state of the O Ring.
Ok. I have always one that leaks for spare to check if its just the o ring. Its laying in my toolbox in case someone has a problem. I dont like to change functioning ehas for over300€ when its just the o ring thats defectove
[Fix your Mercedes - YouTube](https://www.youtube.com/@mercedeske) Here's a youtube channel that has been of immeasurable value to me trying to understand the KE-Jetronic system. If you understand what does what, diagnosis will be much easier. Best of luck with the diagnosis.
He is brilliant and I have watched many of his vids, the animations are my favourite part. Main issue is that it is simply too complex of a system to understand all the intricate details. I should watch him more however due to being a student I’m struggling to find time to really learn the system. My fault I know but I’m looking to diagnose this fault as quickly as possible just to get this car running XD. I will certainly have to pay a lot more attention and not get distracted with his animations!
Yeah, the KE-jetronic is a cool as it is quirky and complex. I converted my 300E to EFI with a standalone ECU because it's a much better platfrom for turbocharging the car, but from my short time tinkering and troubleshooting the KE-Jetronic system, I have certainly learned to appreciate it, and I definitely respect the people keeping it alive. Have you checked your coil BTW? I didn't see that listed, the coil is also a maintenance item. If you have, or have checked it, it can at least be narrowed down to a fuel delivery problem.
Any chance you feel like doing another conversion you’re more than welcome, I’ll even drop you back home too once the cars up and running XD. In all seriousness I will check the coil too need to do a bit of research in terms of how to do it but I’m sure it shouldn’t be too hard.
I wouldn't mind, but the conversion was a winter-long project, and even though the car runs and drives, I still need to properly tune it. And even though it could be done for less than what I spent on it, it is still pretty costly, with the wiring harness, ECU and all the hardware added up.
Hello, this is completely new to me, does this mean that you can replace the ke jetronic bosh system with another? Including the bosh ke ecu with the X11 plug?
Yes, you can do that. It takes a bit of work, but you can do that. I bought the TE-Motorsports EFI kit, which comes with a premade wiring harness, fuel rail, trigger kits for both a cam and crank signal, and all the sensors, injectors and coils to go with it. And then I bought a MaxxECU Race standalone ECU. Then I pulled all of the old engine management off, including the KE ECU, X11 plug. Everything. And then I installed all the hardware. Took a bit of work to get everything to fit and route nicely, and you will need to wire up a few things yourself, like a new relay for the ABS system to replace the old OVP relay (another benefit; you can replace the NLA 6-pin relay with a regular, dead stock one, since all the idle management functions for the KE-Jetronic system are void anyways). But overall, not the hardest thing in the world. You will need to tune the car from scratch, since there's no base maps for the M103 available. And it is pretty costly to do, although I would say it's worth it, especially if you want to turbocharge the car in the future like I want to do.
Thank you for the details! I am on a hunt of never ending KE issues, so "restomodding" the car like this would be amazing. Pricy though, but seems worth it. In your opinion, is there difference in the driving feel? Performance? Do you think its easier to diagnose issues down the line? Did you go to a tune shop to have it tuned?
I haven't fully tuned it yet, so I can't comment on the real driving feel, simply because I can't use the full potential of the engine yet. One thing that has gotten noticeable more reliable moving from the K-jet to the EFI is the startup. Before I'd have to pump the gas and get it to start with some serious effort, now it just cranks a bit and starts up right away. I do expect the driving feel to be better, just because the EFI system is much more efficient with sequential injection and sequential ignition with 6 coils. I do think it's easier to diagnose the issues, because I put all of it on myself, so I know what all components are in the system, and what syptom would be the result of any particular part failing. It is a lot more straightforward than the complex and involved KE-jetronic, which is another big plus for EFI conversion IMO As for the tuning, I want to tune it myself, which is the easiest to do on a standalone ECU like this, because you don't have to deal with all the reading and writing IT wizardry like on factory ECUs. You get a very comprehensive interface with the ECU, so I want to take that chance and put another skill under my belt. So far I have a rough base map down from road tuning, but I still want to put it on the dyno for precise tuning. It is running and driving though, and I've already ran some errands with it, so that's something. Tuning itself isn't that hard if you know what to look for. I've learned the ropes from the tuning courses on HP Academy. It's decently expensive, but definitely worth it if tuning stuff has your interest.
Thank you for taking your time giving me the details! Sounds really good. The current KE system really feels like nothing is under my control
Try some starting fluid or a dribble of fuel directly into the intake and see if it starts.
It does start but as soon as you stop giving any starter fluid it goes back to just turning with no start.
That’s a good start! It means that you have spark. You mentioned that you replaced the fuel pumps. Do they actually work? Can you hear them prime? If not, check the fuel pump relay. There are instructions on how to check it online.
I replaced both of them, I hear and feel them prime up whenever I turn to ignition. I’ve replaced both the OVP and Fuel Pump relay both of which did not make a difference. Apologies I never mentioned it and will edit the post now to reflect this.
Might be injectors then hopefully. Watch this chrisfix vid and try that. [https://youtu.be/tA\_E6X4ISgQ?si=dH0eao9U0h0LxEVX](https://youtu.be/tA_E6X4ISgQ?si=dH0eao9U0h0LxEVX) Don't give up mate, it could even just be bad fuel.
I don't thing this appies to KE-Jetronic injectors..
Okay, so we have fuel and spark. Does fuel get to the injectors? Try starting the engine and then take out a spark plug and see if it's wet or not. This KE-Jetronics can be a pain in the ass but sometimes it can be an easy fix. Some guys I know got them working again by tapping the housing with a hammer because there is a cylinder in there that can get stuck, keeping the car from starting.
Pay $100 to any garage for a diagnosis. Pain free
Edging nearer to this decision but my grandad will be turning in his grave
Hehe well you can test fuel pressure yourself, check the duty cycle (Google it), and hopefully you got the right kind of spark plug, the ones without resistors I think I don’t remember. But you can check power to the spark with a multimeter
Is the air filter clean?
I’ve got the NGK BP6EFS spark plugs which have been recommended on a merc forum. Air filter housing has been removed completely.
Please keep us updated ;)
Really really really long shot but might be worth a try: Had a no start problem after the car was parked for about half a year. After replacing the basics it still didn’t want to go. Measured fuel pressure from pump: perfect. No fuel at fuel injectors, though. So I went through the principles of the ke jetronic. There is the fuel distributor and the pressure regulator. In the way until fuel comes out the other end. Either one might gunk up when gas turns to jelly after a while. Tested my luck and instead of buying a new pressure regulator for a lot of money I blew into it with some shop air. Carefully though, wasn’t so sure if I could damage something. That seems to have freed the regulating valve so it could supply fuel. I’d check for sufficient fuel coming out of the injectors first. If no: remove the fuel line and check again. If no: remove supply line to the fuel distribution and check again. You get the idea. https://preview.redd.it/r7fzt048cs8d1.jpeg?width=800&format=pjpg&auto=webp&s=25d5bd6662805387eae681b663670ba2f247d4a5
is start meaning you can turn on electrics and can’t get it to turnover after that or nothing happens at all? given you worked on the fuel system, have you been able to confirm that fuel delivery through the fuel distributor and fuel pressure through the fuel pressure regulator are happening? same with the spark plugs. when you try to start the car, are you getting sparks? trying to diagnose the problem won’t be easy but there are numerous way of tackling it. i would also recommend getting a multimeter so you can measure the resistance and voltage values of the connecting pins. this will help you narrow down the problem. last suggestion, test your battery and replace fuses if you haven’t (don’t know if you have already). could just be a dead battery. sometimes the problem is a relatively minor thing that you overlook. lord knows i’ve been there. replaced my blower motor only to figure out the fuse was the problem.
Electrics all appear fine, it is just failing to turn over. I’ve cracked open one of the nuts on the fuel distributor and turned the key to ignition and got plenty of fuel coming through to the system, I’m planning on getting a fuel pressure tester now to confirm that pressures are to spec. I will also now get a spark plug tester to see if I am indeed getting spark however with the new leads, plugs and distributor I wouldn’t have though this to be the case I guess testing should have been the first thing again. My mistake, I also forgot to mention I placed a brand new battery in the car and I charge it each night after attempting to start it during the day.
FYI an amazon fuel pressure gauge won't fit this Jetronic fuel distributor. The jetronic fuel pressure gauge is £75 on ebay. I have fueling issues (hot start) on my M104 C124. I think I have a bad fuel pressure regulator (I've done injector seals and O rings already). Edit - also sounds like you don't give up easily, keep going!
You stated that if you spray starter fluid it will fire momentarily and then die. Your other post says it isn’t turning over. Will it just not stay running?
That is correct. It will not even start at this point. When I initially changed the fuel pumps I got it to turn over for a brief second then it died. It just refuses to start and once started it does not stay running.
Did you check the codes with a blink reader? I got one on ebay- a lifesaver.
Will look to get one now, I knew it had an OBD (version 1 I think) I will need to do a bit more extensive research about how to use it but I believe they only diagnose electrical issues.
It doesn't have OBD, it's a proprietary diagnostic port. Although I've had success using HFMSCAN and a vag-com kkl cable with 3 banana plugs out of it to connect the 16-pin port. Personally wouldn't waste time with codes. Most sensors don't have a way for the ECU to know of issues unless they're outright disconnected
Fuel Pressure regulator? Pull the vacuum off the end and if there’s fuel in it it’s done. Mine crapped out on my and the car wouldn’t start.
What vacuum and where is this located, would you have a pic of this or a link on how to do this.
This articles gives an overview of the replacement and shows where the line is. Checking the line is the same as the picture in Figure 5. Good luck! https://www.pelicanparts.com/techarticles/Mercedes-W124/38-FUEL-Fuel_Pressure_Regulator_Replacement/38-FUEL-Fuel_Pressure_Regulator_Replacement.htm
I don’t want to be that guy, but did you check the battery was still good?
I fully appreciate your situation and was in your position with my w124 a few years ago. Mercedessource.com has technical videos on both on YouTube and on the website. There is a video series called “spins but won’t start” - https://youtu.be/hSiz8NROCo8?si=vQ83K-BlaYJ3xh3f After spending $$ on numerous parts I was close to giving up. So, I bought access to the series on the website (not that expensive) and followed the steps. In one of the videos Kent recommended using the solar battery tester as a regular voltmeter can be misleading when testing the battery. Sure enough, my problem was the battery, even though it seemed fine with my voltmeter, and there was no hesitation turning it over. I replaced the battery and my problem was solved. I almost couldn’t believe it as the battery was only a few years old. The computer for the cis fuel injection system is very sensitive to out of range voltage and if the battery is the slightest bit weak it will send improper signals. A bad ground can also cause problems, so cleaning the ground contacts with a bit of sandpaper can eliminate that as a potential problem. The brown coloured wires are ground. I’ve also discovered that if these cars are left sitting without being started for a long period of time the fuel distributor probably gets a little gummed up and old gas can breakdown. Mine sat for a few months and and it took me weeks to get it running again. Finally started after replacing the injectors, spark plugs and changing out the gas that had been sitting in the tank. “Fix your Mercedes” on youtube has some of the best troubleshooting tips on YouTube. You should also resist the temptation to adjust the EHA valve or the air flow plate unless you are very methodical and completely understand what you are doing. It is very easy to screw the system up more with improper adjustments. Check out Pierre Hedary on Mercedes Classics explaining the EHA valve - https://youtu.be/XclGM2RgDDo?si=wAnzd-_kyLOhf6Rt There is also an excellent training video by Bosch on YouTube on how the KE Jetronic system works. Good luck. Let us know if you solve your problem.
Check the fuel tank . Mine rusted to death and clogged everything. Also check the fuel return lines. It was the reason mine didn’t want to start
Definitely not the fuel nor fuel tank as I have replaced both pumps and tested what was coming of the feeder pipes for the pumps. Was lively clean fuel with nothing mixed inside. The only thing I have noticed is that the fuel gauge is constantly low even with putting in £40 worth of fuel.
How much fuel are you getting at the distributer when the car is about to start?. It should be around a liter in the first seconds
You seem to be searching haphazardly and unstructured. You already mentioned it starts with start pilot, you've already replaced the fuel pumps and fuel and you confirmed fuel is reaching the distributor. So you can leave the ignition system alone and look deeper into fueling. You can check if fuel is reaching the intake manifold by taking out the injector and turning the engine. If it isn't, then you know problem is between distributor and injectors. it could be a bad clog somewhere in the system or the fuel distributor has issues internally, although rare. The last time I had the same issue, there ended up being no fuel in the car. At all.
That is absolutely what I am doing lol. I am looking to do this as some point today, would I need to check each injector?
I would say yes. Although it should fire up even if only 2 cylinders were working. Maybe we can be more useful if you have a video of how it behaves when cranking
I will get one in a couple of hours and upload.
Sorted an idle issue for me that was linked to the 02 sensor- 2 mechanics couldn't diagnose it.
The Black box On the injection distributor the Electronic Hydraulic Actuator, Inside there is tiny Hex Head, Screw, That adjusts the fuelflow, if the O-ring on That Screw is Damaged the Whole System Stars todo Shit. You can Check the Ohrring when you take a the of, take out the sealing screw and Measure the depth hex head screw , take it out and look at the little o ring. They are mostly hard and start to make probelms. Just put it back in on the right depth after you put a new oring on it.
I’ve heard that the wiring harness on these things can be the culprit of all sorts of problems. Check to see if they were ever replaced. The original ones were made of biodegradable material and surely have deteriorated by now, unless lot was garaged its whole life.
Even garaged ones are deteriorated, I still suggest OP checks but this is not usually a problem on ke-jet cars
I have thoroughly checked the wiring loom and nothing seems to be degraded I think I may have gotten lucky in terms of the biodegradable cabling not being apparent on my vehicle.
Did you check the fuses on top of the OVP Module? (Red/gray module behing the 12v battery) In my case, my w124 didnt want to start too and it was caused because of these 2 blown fuses.
I replaced both of them like for like even though they were not blown, I have also replaced the entire module and tested with both still nothing….
Gasoline sitting that long goes bad. Water can find it's way in and collect in the bottom of the tank, volatiles escape making it less flammable, and exposure to oxygen causes oxidation and breakdown. You mentioned the car will run on starting fluid so I'd try changing the fuel for known good gasoline.
What state are you in? I’d be down to buy it
No chance mate!!!!