I am thankful that when I had this issue, mine was just the accumulator. I really enjoy this car when it works, but mine is always needing something. Fun to watch this journey of fixing yours up. Thanks.
Great! This regulator is specific to the 3.8L & 5.0L fuel distributors. This part was eliminated in the 4.2L & 5.6L engines and integrated into the EHA Valve. Thank you for sharing this info!
I’ve enjoyed your videos. I had the exact hard start problem when my engine was hot on my 1984 380SL. Your diagnosis is correct about checking pressure by pushing on the plate on the air intake. I will say that the problem with the valve you replaced is usually the small O-ring. It’s exposed to gasoline so it deteriorated. I pulled out the valve and only replaced the O-ring. It’s a specific size and of course Mercedes and the other parts dealers only want to sell you the whole valve assembly for over 200 bucks. I went to harbor freight and bought a box of assorted O-rings in mm size and found 4 of the ones I needed. Cost me 9.99! It’s relatively easy to pull out the valve from the back of the fuel distributor. Just don’t lose the shims. If people have this hot hard start problem check your O-ring first.
@@sophiathe380sl hello friend ,i just bought a 1981 sl 380 i have the same promblem with hot start ,and i live in los angeles ,if you will kind to give me the info about your mechanic please . my name is Guy k.
Hey thanks for the video! Working through similar issues with my 380slc, so every little lead is a huge help! Of course I rebuilt everything in back EXCEPT for the accumulator... Best of luck with the continuing renovation, beautiful car!
Haha. Thanks man. Glad I could help. Accumulator is pretty easy to change. Catch the other video. The screen is where it could get challenging. Good luck.
I read in the user manual how to start warm engine!! Press the gas pedal then crank once the engine starts take your foot off the gas.. works with me..
Hi, just wanted to inform you that I had the same Hot Start Issue and I copied you in replacing the Fuel Accumulator and all went good :). I did change the Fuel Pump, Fuel Filter and the Fuel Hoses as well. So now my system is new like your system except that i changed the Main Hose that goes to the car that you have not replaced (you only bought hhahhaha).
Love the video, it brought to light another possibility on my 85 MB 500sel, if that fix is the same on my car. Actuator has been replaced recently (1yr), but I am going to check for leak just to be sure. Last "mechanic" I used did an expensive crap job, so as usual I rely on my own abilities, to a point. I've put up my MB for sell, so I want to get her starting like she use to, no pedal and little bump to start. Luckily I have a 64 Pontiac Bonneville wagon that has been reliable for over 40 years.
@@sophiathe380sl update, I have, after fixing all vac leaks after my smoke tests, and still have the same issue you had, namely the car after it starts and runs (perfectly) for a short time i then turn it off, I can restart with no problem, but after 15-20 minutes the plate drops in easily and the car cranks for a while before finally starting again. As long as I start it right after turning it off, it starts with no problem and runs fine, but leave it for a while and then it is hard to start. SO, looking to replace the Mercedes 500SEL Fuel Distributor Valve Kit. Fuel Distributor Valve Kit CS-SKU 400:29679GX
@@dannywilliams9045 I have no idea. This was done by the mechanic. I think you need some additional pressure diagnostic tools. More than I can handle at home.
Thanks mate for the video. I'm looking at your other videos too. I have a '76 350SL 107 and have the same hot start issue. And the engine won't even start from yesterday. But i'm going to replace the weak fuel pump first, then look at the accumulator. As far as I know, most 107 123 116 fuel pump does make a hissing sound when idling. Mine can't start at all so I connected pump directly to a battery and it works ever so slightly, with faint vibration felt when holding it. Hence why I'm replacing the pump first. One more thing, when I checked for 12V there was no current supply with key switched on. But when cranking, there was 12V supply. Is this how it's suppose to be?
That part there is called the primary-pressure regulator which is incorporated in the fuel distributor housing. When the engine is running it maintains the pressure in fuel system constant. After the engine has been switched off, the fuel pump also stops running and the pressure regulator closes the return-flow port back to the fuel tank and prevents pressure reduction in the fuel system to facilitate restarting, particularly when the engine is hot.
Thanks for explaining that! Is it a common issue? I’m guessing with the right diagnostic tools, you can find what’s failing without throwing parts at it.
@@sophiathe380sl Mine was doing same thing when I picked it up in 2017, and turns out rust in the tank had clogged the botton fuel screen preventing fuel to leave the tank, and it would become dislodged during driving and once warmed up & at stop light, car would die, I would pull over, open fuel cap, and hear a woosh of air, put cap on and start and drive another 10 minutes & repeat
Im having some issues with cranking and no start at all when cold. Two suggestions for you. (1) Think about removing those aftermarket chrome fender bling - moisture gets trapped under there and can rust out your car, and (2) CHECK you front subframe for cracks....MBZ issued a recall but did not include the 380 series. Your wheels can fall off at any moment.
Thanks for the suggestions. 1. Yes, hate them. I’ll pull them soon. 2. Mine already cracked. I actually made 2 videos on it here on the channel. I had to replace it with a 560sl subframe. So dangerous… Any future video ideas are welcome. Thanks for watching!
I don’t recall if you have a fuel pressure gauge yet from watching your other videos, if not, I own this gauge Tool Aid 38000 and it has everything you will ever need plus some and has the needed separate shutoffs to be able to safely test control pressure. On the fuel distributor, these are a source of many issues over time and need regular rebuild as these cars often sat for years (hence lower mileage and still around) with old gas and the diaphragm and it’s tiny holes get gummed up. For a fuel distributor rebuild, often the part you had an issue with is not touched as it is frequently not the issue. Yours may have been gummed-up. You can rebuild a fuel distributor yourself or get one rebuilt. Quixtarstp on eBay did mine most recently (I bought a rebuilt one and kept my old one) as I didn’t want to do it, he did a good job. Removing and installing the fuel distributor is well within your abilities if needed in future. You may need to use a screw extractor and a hand (manual) impact hammer to get existing mounting screws out and thus you may need new screws, quixtarstp sells those also. Buy a copper washer assortment for any fittings. The fuel distributor can cause a huge range of issues including rough idle. It is often overlooked as a cause of rough idle. My car has an exceptionally smooth and quiet engine after a fuel distributor rebuild. Failure of fuel distributors is correlated with failure of the accumulator and similar items- old sitting gas. For example, as you may recall I’ve had my 380sl for 30 years. 15 years ago I installed a rebuilt fuel distributor. Very little mileage since then but distributor began degrading about 5 years ago (rougher idle) and progressively delivered very rough idle and rich running until I changed it again this past year. I recommend getting a rebuilt fuel distributor and keeping your old one with another purchased rebuild kit in your stock for future, the gasket kits are still readily available today. After 30 years I have had the habit of keeping extra parts and this has helped me quite a bit over the years. For example, years ago the vacuum idle controller was readily available but today very expensive and only available used typically. I also saw your reference to vacuum in another video. Despite what’s written online, often this is not the cause of all woes. Good vacuum is still valuable. I became tired of worrying about door lock, trunk, and ac vacuum leaks. I plugged the vacuum lines to these at the firewall and that is also where I measure standard vacuum. Plugging this gave me a nice vacuum improvement and cost me nothing as I couldn’t care less about power door locks etc. one final note, note there are two types of vacuum: ported and what I call standard. One vacuum increases as you depress the accelerator, the other decreases. In contrast to many incorrect posts online, the truth is you will get different vacuum readings around the car based on where you measure, type of vacuum, and proximity to leak. At idle you want to see 15hg plus typically or better. Measuring while driving, interesting but not always required, will show you how your vacuum decreases and recovers. Again though micro-analyzing vacuum and fuel pressure or using an oscilloscope to measure the fuel injector frequency valve pulses all can consume a good deal of time when, in the end, the culprit was the need to rebuild the fuel distributor.
Do some body know what is wrong with my 380sl 1985? I changed the timing chain, I know I done a good job on it, according to the repair book, it overflowed and do not crank at all, I found gas in the muffler, to much, it was dripping from, thanks in advance to y'all guys.
I don’t have a warm or hot start issue. But I do have an overheating issue. And also my oil smells of gasoline. Still haven’t figured out that issue. I’m at a loss. I changed the oil the day before yesterday. And it’s back to smelling like gasoline. So I wasted $80 in oil…
@@sophiathe380sl I’m not sure that is it. Coolant level is the same. There isn’t any coolant in the engine oil. I have been told it would be foamy if that’s the case, right?
@@joshuaculley9695 ya, I’ve heard that it’s foamy. I’m not sure. I’d take it to mechanic. Open the reservoir and smell the fluid. I wonder if it smells like gas.
@@sophiathe380sl the coolant reservoir? I’ve got an appointment Monday with Mercedes. They have like one guy who is knowledgeable about these older cars I booked it months ago
@@sophiathe380sl are you on Instagram or anything? I have an 83 380sl that’s been sitting for 4 years now after a broken subframe. Always looking for more information. Thanks
@@sophiathe380sl I had drove to pick up my daughter from school. I got all the way there and it broke when I reversed out of a parking spot with the two of us in the car. I’m glad it broke there and not when we were driving. Good luck with everything.
Since the mechanic did it, I’m not sure. He made it sound like it was on the back side of the distributer. It comes with shims so maybe those are required for adjustments.
@@sophiathe380sl sorry, I will explain better this time. I live in the middle East and I noticed the warm start issue occurred only when the outside temperature is 100 degrees and above! Otherwise it fires right up, I think its fuel vapour lock caused by the heat..
This is what a video looks like when it’s made by someone who doesn’t work on cars, but can regurgitate what the mechanic told them an hour ago, and can’t even do that well.
These Mercedes are so packed with crap it’s amazing. What happened to a fuel pump moving gas through a line from your gas tank to a filter to your carb and out your exhaust?
I am thankful that when I had this issue, mine was just the accumulator. I really enjoy this car when it works, but mine is always needing something. Fun to watch this journey of fixing yours up. Thanks.
Thanks for watching. I’m glad you guys are enjoying them.
Great! This regulator is specific to the 3.8L & 5.0L fuel distributors. This part was eliminated in the 4.2L & 5.6L engines and integrated into the EHA Valve.
Thank you for sharing this info!
Thanks for your help and guidance along the way. Much appreciated
I’ve enjoyed your videos. I had the exact hard start problem when my engine was hot on my 1984 380SL. Your diagnosis is correct about checking pressure by pushing on the plate on the air intake. I will say that the problem with the valve you replaced is usually the small O-ring. It’s exposed to gasoline so it deteriorated. I pulled out the valve and only replaced the O-ring. It’s a specific size and of course Mercedes and the other parts dealers only want to sell you the whole valve assembly for over 200 bucks. I went to harbor freight and bought a box of assorted O-rings in mm size and found 4 of the ones I needed. Cost me 9.99! It’s relatively easy to pull out the valve from the back of the fuel distributor. Just don’t lose the shims.
If people have this hot hard start problem check your O-ring first.
Wow! I wish I would have known that. Thanks for watching!
@@sophiathe380sl hello friend ,i just bought a 1981 sl 380 i have the same promblem with hot start ,and i live in los angeles ,if you will kind to give me the info about your mechanic please . my name is Guy k.
@@guyk4819 Hey Guy. Where do you live in LA? Send me an email. Turbo272727@hotmail.com
problem with Harbor freight Chinesium O-rings is they disintegrate over a shorter timeframe
Hey thanks for the video! Working through similar issues with my 380slc, so every little lead is a huge help! Of course I rebuilt everything in back EXCEPT for the accumulator... Best of luck with the continuing renovation, beautiful car!
Haha. Thanks man. Glad I could help. Accumulator is pretty easy to change. Catch the other video. The screen is where it could get challenging. Good luck.
Thanks for the heads up and good information on the video.
Mine cranks but does not start so I’m looking at the accumulator. Hoping that’s all it is.
I read in the user manual how to start warm engine!! Press the gas pedal then crank once the engine starts take your foot off the gas.. works with me..
Thank you from France 😊
The warm up regulator creates this problem too. I’m currently replacing mine too.
Hi, just wanted to inform you that I had the same Hot Start Issue and I copied you in replacing the Fuel Accumulator and all went good :). I did change the Fuel Pump, Fuel Filter and the Fuel Hoses as well. So now my system is new like your system except that i changed the Main Hose that goes to the car that you have not replaced (you only bought hhahhaha).
That’s great!
Still have my MB long shaft torx driver, to go through the breather, and adjust the fuel distributor.
The fuel accumulator was my hot start issue. I used a little starting fluid to get it started until I figured out the issue
Sir. I have a 1972 350 sl Eu model great car your videos are just great, thanks living in Denmark, have a great day and THANSK, ARTHUR
So nice. Thank you for watching and the comment!
Love the video, it brought to light another possibility on my 85 MB 500sel, if that fix is the same on my car.
Actuator has been replaced recently (1yr), but I am going to check for leak just to be sure. Last "mechanic" I used did an expensive crap job, so as usual I rely on my own abilities, to a point.
I've put up my MB for sell, so I want to get her starting like she use to, no pedal and little bump to start. Luckily I have a 64 Pontiac Bonneville wagon that has been reliable for over 40 years.
I try to do as much as I can before taking it to a real mechanic. 😂 good luck.
@@sophiathe380sl update, I have, after fixing all vac leaks after my smoke tests, and still have the same issue you had, namely the car after it starts and runs (perfectly) for a short time i then turn it off, I can restart with no problem, but after 15-20 minutes the plate drops in easily and the car cranks for a while before finally starting again. As long as I start it right after turning it off, it starts with no problem and runs fine, but leave it for a while and then it is hard to start. SO, looking to replace the Mercedes 500SEL Fuel Distributor Valve Kit.
Fuel Distributor Valve Kit CS-SKU 400:29679GX
@@dannywilliams9045 Yup! That’s what fixed it for me.
@@sophiathe380sl can you just purchase the small "O" ring separately?
@@dannywilliams9045 I have no idea. This was done by the mechanic. I think you need some additional pressure diagnostic tools. More than I can handle at home.
Thanks mate for the video. I'm looking at your other videos too. I have a '76 350SL 107 and have the same hot start issue. And the engine won't even start from yesterday. But i'm going to replace the weak fuel pump first, then look at the accumulator. As far as I know, most 107 123 116 fuel pump does make a hissing sound when idling. Mine can't start at all so I connected pump directly to a battery and it works ever so slightly, with faint vibration felt when holding it. Hence why I'm replacing the pump first.
One more thing, when I checked for 12V there was no current supply with key switched on. But when cranking, there was 12V supply. Is this how it's suppose to be?
That part there is called the primary-pressure regulator which is incorporated in the fuel distributor housing. When the engine is running it maintains the pressure in fuel system constant. After the engine has been switched off, the fuel pump also stops running and the pressure regulator closes the return-flow port back to the fuel tank and prevents pressure reduction in the fuel system to facilitate restarting, particularly when the engine is hot.
Thanks for explaining that! Is it a common issue? I’m guessing with the right diagnostic tools, you can find what’s failing without throwing parts at it.
@@sophiathe380sl Mine was doing same thing when I picked it up in 2017, and turns out rust in the tank had clogged the botton fuel screen preventing fuel to leave the tank, and it would become dislodged during driving and once warmed up & at stop light, car would die, I would pull over, open fuel cap, and hear a woosh of air, put cap on and start and drive another 10 minutes & repeat
Im having some issues with cranking and no start at all when cold. Two suggestions for you. (1) Think about removing those aftermarket chrome fender bling - moisture gets trapped under there and can rust out your car, and (2) CHECK you front subframe for cracks....MBZ issued a recall but did not include the 380 series. Your wheels can fall off at any moment.
Thanks for the suggestions. 1. Yes, hate them. I’ll pull them soon. 2. Mine already cracked. I actually made 2 videos on it here on the channel. I had to replace it with a 560sl subframe. So dangerous… Any future video ideas are welcome. Thanks for watching!
Ummm, the NEW injectors shouldn't leak... Mine don't and I tested them on my New tester, prior to install
I don’t recall if you have a fuel pressure gauge yet from watching your other videos, if not, I own this gauge Tool Aid 38000 and it has everything you will ever need plus some and has the needed separate shutoffs to be able to safely test control pressure. On the fuel distributor, these are a source of many issues over time and need regular rebuild as these cars often sat for years (hence lower mileage and still around) with old gas and the diaphragm and it’s tiny holes get gummed up. For a fuel distributor rebuild, often the part you had an issue with is not touched as it is frequently not the issue. Yours may have been gummed-up. You can rebuild a fuel distributor yourself or get one rebuilt. Quixtarstp on eBay did mine most recently (I bought a rebuilt one and kept my old one) as I didn’t want to do it, he did a good job. Removing and installing the fuel distributor is well within your abilities if needed in future. You may need to use a screw extractor and a hand (manual) impact hammer to get existing mounting screws out and thus you may need new screws, quixtarstp sells those also. Buy a copper washer assortment for any fittings. The fuel distributor can cause a huge range of issues including rough idle. It is often overlooked as a cause of rough idle. My car has an exceptionally smooth and quiet engine after a fuel distributor rebuild. Failure of fuel distributors is correlated with failure of the accumulator and similar items- old sitting gas. For example, as you may recall I’ve had my 380sl for 30 years. 15 years ago I installed a rebuilt fuel distributor. Very little mileage since then but distributor began degrading about 5 years ago (rougher idle) and progressively delivered very rough idle and rich running until I changed it again this past year. I recommend getting a rebuilt fuel distributor and keeping your old one with another purchased rebuild kit in your stock for future, the gasket kits are still readily available today. After 30 years I have had the habit of keeping extra parts and this has helped me quite a bit over the years. For example, years ago the vacuum idle controller was readily available but today very expensive and only available used typically. I also saw your reference to vacuum in another video. Despite what’s written online, often this is not the cause of all woes. Good vacuum is still valuable. I became tired of worrying about door lock, trunk, and ac vacuum leaks. I plugged the vacuum lines to these at the firewall and that is also where I measure standard vacuum. Plugging this gave me a nice vacuum improvement and cost me nothing as I couldn’t care less about power door locks etc. one final note, note there are two types of vacuum: ported and what I call standard. One vacuum increases as you depress the accelerator, the other decreases. In contrast to many incorrect posts online, the truth is you will get different vacuum readings around the car based on where you measure, type of vacuum, and proximity to leak. At idle you want to see 15hg plus typically or better. Measuring while driving, interesting but not always required, will show you how your vacuum decreases and recovers. Again though micro-analyzing vacuum and fuel pressure or using an oscilloscope to measure the fuel injector frequency valve pulses all can consume a good deal of time when, in the end, the culprit was the need to rebuild the fuel distributor.
@eric Thank you for all that info
@@sophiathe380sl your welcome, I just did about 5 edits for typos so you might re-read for those corrections.
same issue, found to be the starter/ ignition relay in the fuse box under the hood.
Did that happen only when warm though?
@@sophiathe380sl yep. only when it got warm.
@@ricdrakes2741 hmm. Another reason this thing won’t start when warm. 🙄😂
@@sophiathe380sl so remove the starter relay when it wont start, and run a jumper wire in its place, if it starts you know its the relay
@@sophiathe380sl Easiest to work on , most well built cars around, but parts are expensive.
my 76 450 got a new MSD ignition system and all new aftermarket EFI........ Bye Bosch !
hi are the wheels original, if not where did you order the wheels from?
Hi. Yes, original chrome wheels
When you say push on the plate to test the pressure, where is that plate exactly? Appreciate all the videos. Very helpful! Thanks
found it on your other video. cheers man. very helpful.
@@luispereira7793 great, I was just about to send it to you. Thanks for watching and I appreciate you defending me with that other fool’s comment. 😂
Good vid, I subscribed
Hello! Can you please tell me where the fuel pump relay is located? Thank you.
Hello. I’ve never removed mine but I think it’s under the glove box. There are a few videos (not mine) on UA-cam to watch. Good luck!
Thanks for the tip.@@sophiathe380sl
Do some body know what is wrong with my 380sl 1985? I changed the timing chain, I know I done a good job on it, according to the repair book, it overflowed and do not crank at all, I found gas in the muffler, to much, it was dripping from, thanks in advance to y'all guys.
I would ask in the Facebook groups or benzworld forums. I’m not sure how many viewers are checking in here 😀
I had to change my Fuel Distributer out about a year ago for a similar issue.
I don’t have a warm or hot start issue. But I do have an overheating issue. And also my oil smells of gasoline. Still haven’t figured out that issue. I’m at a loss. I changed the oil the day before yesterday. And it’s back to smelling like gasoline. So I wasted $80 in oil…
Is your coolant mixing with oil/gas?
@@sophiathe380sl I’m not sure that is it. Coolant level is the same. There isn’t any coolant in the engine oil. I have been told it would be foamy if that’s the case, right?
@@joshuaculley9695 ya, I’ve heard that it’s foamy. I’m not sure. I’d take it to mechanic. Open the reservoir and smell the fluid. I wonder if it smells like gas.
@@sophiathe380sl the coolant reservoir? I’ve got an appointment Monday with Mercedes. They have like one guy who is knowledgeable about these older cars I booked it months ago
@@joshuaculley9695 yes, coolant reservoir. At the dealership? That sounds expensive. Let us know the outcome. Also, how hot is it getting? To the red?
0:40 EXACTLY what mine just started doing!!! Hurry!!! How did you fix it?!?! I’m so excited!! (back to the video)
Where are you ordering your parts? Thanks. Great videos!
Thanks man. Usually AutohauzAZ or fcpeuro
@@sophiathe380sl are you on Instagram or anything? I have an 83 380sl that’s been sitting for 4 years now after a broken subframe. Always looking for more information. Thanks
@@christodd2892 No instagram… wow, perfect timing. My subframe just cracked.
@@sophiathe380sl I had drove to pick up my daughter from school. I got all the way there and it broke when I reversed out of a parking spot with the two of us in the car. I’m glad it broke there and not when we were driving. Good luck with everything.
@@christodd2892 Scary. I drive around with my son all the time. Keep watching. Let’s see how it goes. Haha
Is this valve sitting inside fuel distributor? What is the location to change this part?
Since the mechanic did it, I’m not sure. He made it sound like it was on the back side of the distributer. It comes with shims so maybe those are required for adjustments.
@@sophiathe380sl ok thanks
Can you send me to kods of you change of parts please 🙏
It’s on the paper in the video. That’s what the mechanic changed.
High fuel pressure when outside temperature is hot!!
?? Can you please explain? The car is running great now.
@@sophiathe380sl sorry, I will explain better this time. I live in the middle East and I noticed the warm start issue occurred only when the outside temperature is 100 degrees and above! Otherwise it fires right up, I think its fuel vapour lock caused by the heat..
@@gusibrahim6961 Ahhh, got it. Thanks
Ethenol fuel kills them fast
This is what a video looks like when it’s made by someone who doesn’t work on cars, but can regurgitate what the mechanic told them an hour ago, and can’t even do that well.
Then you can stop watching.
get a life dude. videos like this are very helpful.
There are always some idiots that have to add their stupid comment
Thank you!! Off to check my accumulator! What went bad on that circuit pressure regulator? Can you remove it and see if it’s bad by looking at it?
You’re welcome! I had to get a mechanic involved to fix it. You can go back and watch my accumulator replacement video.
These Mercedes are so packed with crap it’s amazing. What happened to a fuel pump moving gas through a line from your gas tank to a filter to your carb and out your exhaust?