Fuel Pressure accumulator what do you do 

After 3 years of this video published, still helping people just like me. This will keep helping people after many many years. Thanks.

This fuel accumulator fixed a long crank on my dad's 420SEL. Save old school Benzes!

I've been so frustrated at times so I thought of getting rid of it but because of your videos and your knowledge you have saved me thank you

I have an ‘83 380 SEC, 130,000 mi, I was having erratic idling issues, poor gas mileage & lack of power, my mechanic is in the process of replacing the fuel accumulator, idle air valve & warm up regulator. Hopefully this will resolve the problems. Hard to find parts and 4 hrs labor $1,700 total! I enjoy your videos it gives my info so I understand the mechanic

One of the best channel for owners of classic Mercedes Benz.

Pierre is the man!! Always helpful and approachable I’ve learnt so much from these videos

Thanks for your efforts I have a 81 VW Rabbit pickup with CIS so found you !

This video did help me figure out hot start. Previous guy replaced the pump and filter, but not this part. It's super easy to change, but don't make the mistake I did and not clamp off the small line. That lead to me taking about a 2 gallon gas shower.

Appreciate your videos. I've watched several of them, and you've helped me get my K-Jet system sorted on my Delorean. Thank you!

Pierre really has the most helpful and useful automotive channel on youtube.

Great helping information for trying to source an problem that has plagued my 450 SEL 1976 .

I bought my S320 with a bad fuel pressure accumulator. The "shop" wanted over $200.00 to put a new one on. I looked up the price of the Bosch part, watched on RU-vid somebody show me how to do it the "proper" way and quickly understood why the book value of the repair was so high. You gotta rent a bay overnight for the car to cool down, a good-looking young lady to stand by with a fire extinguisher and an $18.00 C-clamp tool that works like pliers, but backward. I did it myself for

Very interesting, I've always held Bosch products in high esteem. Thumbs up.

Thank you-Thank you Sir!!! I've just solved my 1989 MB 300ce problem. I haven't been able to drive it since it couldn't stay running unless I keep spraying starting fluid...Thank you again Sir!

Very good. Describes my symptoms for w124 starting issues. Thank you

Like I have said in other videos I have bought a 1987 560 SL but I watch your videos and most of the time I will pickup useful information.

Had a hot start issue on my 88 Esprit with KJet. After watching this video last week, I replaced the accumulator. No more issues. Thanks a lot.

Pierre, I do believe the small line off the back is a leak line, that will only have fuel come out if the accumulator has failed, i.e. the diaphragm is leaking. I believe the diagnostic test in the manual has you remove the small hose from the accumulator and pressurize the system, no fuel should come out of the fitting. I don't have the manual in front of me, but that's how I remember it.

Helpful because my Mercedes was doing just that, now I know where to look for problems 🙏💕Thank you 🙏🙏

I find your delivery of info excellent. I'll strive to support!

Thanks for probably sorting out my issue

100 % agree with what you say I trained & qualified as a Mercedes mechanic and worked with them for 35 years & do not recall renewing a fuel accumulator on a R 129 ever my own car had a blown head gasket and subsequent misfire on start up cold when I bought it quite normal with a blown head gasket I was quite perplexed when the head was done & still had a cold start issue and intermittent felt it could be injectors dripping because of the misfire which occurred after it started with a bit of logic and messing around with basic steps was able to resolve the issue. You can resolve any problem if you throw money at it but it is much better to get the diagnosis right and save money. Great Channel Pierre I watch sometimes as you can never stop learning & always good to get proper advice any one reading this comment this man knows his Mercedes no doubt (solid advice)

Great way to explain the Mercedes gas acumulator.

Thank you and appreciate you sharing your knowledge with us all. I have a 1993 190E 2.6L that is hard to start when cold. It stumbles, shakes, stutters and takes about three cranks on the ignition key when it finally stays on. I will be replacing the fuel pumps, accumulator, fuel pressure regulator, and fuel injectors as they’re all original (30 yrs old). Thanks again!

Yes, you may have solved my COLD start problem on my 500sl. Crank and crank and crank during cold before starting. I did a ez test and seems to indicate what you say about " possible cold start too" problems. Turn the key on and off 3-4 times before starting which allows pressure to build I can hear the fuel pump and it starts right up. After that it starts and drives great no HOT start problems

Perfect advise, perfect video. Thanks.

Excellent thanks. You only know your car when you come to a problem. No hot start problem 190e. I recently had a fuel strainer at the bottom of the fuel tank, the wire mesh screen disintegrated and lots of rust got into fuel line. I had to change the fuel filter and the fuel pump out but did not change the fuel accumulator. Now I have hot start problem. Guess where the hot start problem might be located?

Thank you Pierre,wish you were in Melbourne Australia.Keep up the good work.

Thank you

Interesting, I'm thankful for diesels much more reliable

Thanks for the help! This confirms how my wagon is acting. I believe the fuel accumulator is bad on my 1994 e320 wagon. I will replace the accumulator and fuel filter this weekend.

Thanks for this great video. I will try this, had a major hot start problem with my 560 SEL 1987. Very annoing. Greatings from Iceland. Friðrik Hagalín Smárason

THANK YOU THANK YOU THANK YOU for using vehicle model numbers, such as 450SL, 450SLC, 450SE, 450SEL, instead of just chassis numbers W116, W124, etc.

Thanks

Thanks for the explanation!

youre knowledgdr reaching me here in the Philippines

Thank you for the info. It was extremely useful.

Very good information on the accumulator . Thank you . Trevor Hadlington uk

Thank you so much for your help :D

Thank you sir another really helpful video.

Am driving a 380 v8. Am having the problem with hot start. In the morning the car is so impressive but after driving around and once you have stopped for a quick jump out and upon coming back to start it you have to crank a lot of times with stepping on the petrol. Will definitely take a look at replacing those parts. Thank you for the insight

This is my car problem! Thanks for the video!!!

Great explanation.

Thanks buddy you are a great help 👍

My 450SE has the two fittings on the end. One in, one out, & other end for return to tank, or return to damper.

Thanks for explaining the purpose of these!

Great information Pierre. Like you said a smart mechanic would confirm a bad accumulator. I’ve never done exactly that , I suspect mine is going bad because of the hot start issue. I would imagine you could confirm the failing of the accumulator by putting a vacuum on it (like the vacuum door lock pods) and if they don’t hold vacuum they fail. Or maybe in-line fuel pressure test and watch the residual pressure drop when the engine is switched off.

Great video, but I would like to see how this is diagnosed. I see many people quick to blame the accumulator for a hot start problem when in fact anything that wont hold pressure could cause the problem, injectors, cold start injector, check valves etc.

My 450 1979 SLC has this hard start. They told me to press the gas pedal to start it. I thought fuel injection cars did not need to have the pedal pressed. Now that i saw this video on a fuel accumulator...this might be my next step. thanks for the info.

Very informative and well described!

Going to try a new accumulator on my 85 380 Se to solve a hot start issue.

Answered some good questions! thumbs up!

Debería hacerlo en España para poder aprender y entender todo .

As per usual cobba wonderful thank you mate for your effort

thank you to share your knowledge Pierre

Thank you. Trying to sort out fuel system on 560SL

Just replaced mine (hot starting issues) on an '88 300SEL about 6 months ago. Fixed the issue, three weeks ago started having a random stall issue which turned out to be the fuel pump. Just replaced that today. Not sure if they were original but they both were very old. They were not awfully expensive the accumulator was more than the pump as I recall. Mechanic says I should carry a spare fuel pump relay - as a bad one can leave you stuck.

I’m learning buddy 👍

Mine failed (on my 79 scirocco). In a metal lathe I turned off the flange that holds the two halves together, machined two rings that can be bolted together with M3 bolts, then purchased fuel capable rubber sheet from mcmaster-carr. Using the existing fabric reinforced diaphragm inside the accumulator, I laid down over that a piece of the rubber sheet, trimmed in flush to the flange, and then clamped it back together with the rings I machined. It seems to work fine now.

Greetings from Greece and thank you very much for all of your information and help! I'm a relatively new owner of an 89' 200E w124. Had some problems with starting (mainly cold) and changed the accumulator (sadly used a üropars one). Cold starts are now a little bit better, but hot starts are way worse... Most of the times its fine, but some times it takes way too much cranking to start. Sometimes a green light lights up in the dashboard while I'm driving, and when that happens I know that if I turn the car off, it's going to be a pain to start again. Sometimes no light comes on, but it does struggle, and sometimes there's no problem at all... Could the new accumulator have failed soo quickly? (Less than a month) I have spare one that's OEM but don't know how long it has been sitting

Nice info

The fuel pressure can be tested at the CIS with a handheld pressure gauge. If the fuel pressure drops within the first 10 to 15 mins after engine shutdown under a certain level (depending on the type of engine) you can determine fuel-leak or an accumulator failure and you will have no warm-start. Guess how i know - it is described in the WIS.

Great video, where’s the charge $$..the older guy with the doctors coat and wig wanted money off me..

Thank you for that!!

nice comment below

Great video. This fixed my problem about 6 months ago. The warm start cranking has returned!! Changed the injectors but still an issue. What next? Thanks for the help.

Thanks pro 👍

Hello, I disagree with you when you say in the second minute and about 10 seconds of this video that it is normal for fuel to return through the thinnest pipe to the fuel system and that it is at a pressure of 5.5 to 7 bar. With the thinnest conduit, the fuel is evacuated to the tank only in the event of a leak in the membrane, i.e. fuel pressure accumulator damage. But thank you for the video, made me realize the role of this part in hot engine start.

Thanks bro

Fixed my 92 Audi 80s starting issues! Those accumulators are expensive tho 😬

Thanks for this! Now I know why my 280SE 4.5 was so hard to start when hot.

Greetings. I've watching your videos trying to resolve the problems in my 1990 300E 6 cyl Bosch fuel injected sedan. The car sat for over 2.5 years and upon getting it back I drained out as much old gas as I could and sweetened it up with fresh gas, changed oil and put in new battery and then tried to start it. Once I got started (which was pretty straight forward and quick) it at first bucked and coughed for bit and stalled a couple times but after a short time it settled down into a slightly rough idle but she idled and stayed running on her own. Now the first time I hit the gas it stalled instantly. It soon became apparent that idle was the only thing it was willing to do. So I started checking out all the usual suspects, fuel pumps were running, good spark at plugs, 5.5 bars fuel pressure, (working) good grounds and 12 volts at coil and anything else I could think of. This is where it gets strange. I opted to loosen a fuel line while it was running. I cracked loose what I assume is the return line that being the one that comes off the end of the fuel pressure regulator. Instantly apon loosening this line the car revved up over 2000 rpm which is significantly higher than it had revved so far. Now with fuel pissing out all over the place I ran the throttle by hand and it revved up just fine. I ran it up and down through it's rpm range and let it settle into an idle. Lo and behold she seemed fixed. It ran fine for 3 days, that being Everytime id start it and then I had time that day to change the fuel filter. I figured we sucked up enough crud and bad gas from the bottom of the tank so it was due. It went quickly with no real problems at all except for when I was finished and went to start it and found myself back on square one again with an idling car that stalls instantly apon my giving it gas. Nothing has seemed to help at all this time and I've been checking everything I think of. MAF, Fuel pressure both system and line or working and line, TPS, collector, getting fuel to injectors although it only dribbles out the fuel line from the fuel distributor to the injector. There's a few more things I've checked that won't come to me now but you get the idea. The first time I cracked the line fixing it I assumed it bled air out of distributor or something, now I'm thinking maybe the sudden pressure drop let some groups break free in the injector pump, fuel distributor. I don't know and hoping someone here can suggest something to me so I can have a eureka moment! Thanks in advance and I've enjoyed the videos and clicked like and subscribed to the page. Thanks again

thanks im working on 79 porche 924 dealig with fuel issues now and one thing seems to always lead to another

The serial number of the first Bosch is not correct, can you please clarify its number again. Thank you in advance!

Hi I have a 1990 W124 200E with a 2.0 l engine. The car cold starts well but once hot I have issues in restarting and it takes me abt a min or two to get the engine fired up. After watching yr vdo could it be that my fuel accumulator may be bad? (Once the engine fires up, it runs nice and smooth!)

Great video. Had the same problem with my 380 and replaced accumulator. Hot starts were pretty good now. After a year they degraded again. I unplugged the line on the other side of the accumulator and there was still some dripping coming out after the car was running for a few minutes on the jacks. Not sure how long I have to run to stop dripping completely? When I tested the first accumulator by unplugging the backside, fuel was continuously pouring out the back so the bladder was ruptured. The second one I don’t know if I have a small rupture since it’s a smaller drip. I did order a Bosch replacement accumulator from pelican parts. Not sure if there was maybe something wrong from manufacturing. Can the later version small accumulator retrofitted into an 83, 380sl?

What’s the part number on the accumulator with two ports on top and one on the bottom?

thank u

So, i was thinking that since it's that time of year, maybe you could tell us in a video what type of classic mercedes would be best suited for a zombie apocolypse.

I hope you read my post, today being Nov.29 2022. At any rate I recently restore a 1982 MB W123 M102 engine 2.30SE and I intend to make adjustments on my K-Jetronic. I bought me a repair kit for the fuel distributor and its related components. It idles high with some noticeable slight change in RPM. Id like to know where to start checking. Is it also possible to use scope? Thank you.

great video. my w201 hesitates starting in the morning. other times it will start then die immediately. it also happens after driving the car for more than 1/2 hour then park/kill engine then try to start after 30 or more minutes. acceleration is good - no hesitation. starting is an issue but not a big issue. I don't want to throw parts at it :) please advice.

You said double line acc the fuel flows into acc then out acc into filter then out filter to engine. Reality is from pump to filter out filter in acc out line 2 on acc to engine

hi I have a mercedes sl 300 cab model year 1993. my question is, when the car is cold it starts, when it is warm it cannot be started until it has been sitting for a few hours, then you can start it again. can you the error would be very grateful🙏

Hi Pierre, I have a 73 450SE, I believe its D-Jet? Car cranks but no start. Battery fully charged, fuses and fuel Lim rely work, I hear the fuel pump when key is in position 2. Would crank no start issue be the Fuel Pressure Regulator? I should also add, probably time for a fuel filter and new fuel pump but trying to isolate before throwing unknown parts. Your advice is greatly appreciated!

Pierre, Good morning from Thailand. Perhaps you may be able to shed light on the cause of my W 124 E300 fuel problem. After sitting for a long period of time, perhaps a week or so, the engine cranks but won't start. Removing the inlet fuel line from under the hood and cranking the engine no fuel will come out. I poured some fuel directly into the air intake and the car starts no problem. removing the fuel line again and turning on the ignition fuel spurts out. My diagnosis, and I hope you will confirm, is the accumulator is u/s. I would appreciate you advice.

What is the cause of the engine vibration, and also what is the cause of black smoke coming out of the exhaust when you hit it suddenly?

Quite unlike Lee Iacocca’s K cars. 😉

Have you ever cut one open before? Ford Bosch K Jet (sealed unit) long spring under high pressure, Mine failed now replaced.

Im have a rolls royce 1982 n makr explosión when im press the gas.

Hi, You mentioned an accumulator also provides a pressure for use under acceleration. Could a failing accumulator be the source of my ‘stumbling’ under acceleration? Both cold and warm starts seem to be fine. 86 300SL M103.

Hi, thank you for this vidéo, my M103 engine won't star when it is hot somebody told to chek the fuel accumulator, do you agree ? thank you for your help

1987 560SL stalls after warm-up under load. Replaced both fuel pumps, filter, baffle inside fuel tank, fuel pump relay behind glove box. It will stay running if I spray so I'm sure it's fuel related. Any help would be greatly appreciated.

I'm working on a 74 450sl and when I have someone turn key to start there's only a small click at the fuel pump . Is it supposed to run or is it because it has pressure and that's what stopping it from running my thoughts are the pump is no gd .thanks for the great videos

Thanks for this! I’m having trouble with hot starts on my 88 560SL. BenzWorld has pointed me towards swapping the accumulator. Would you recommend that as a fix?

How do I find out if my 1985 500 sec is sending fuel from the pump, new pump and filter , have spark but does not want to run with out starting fluid

I changed that and my Benz still hard to start

IS COLD START PROBLEM IS THE SAME ISSUE IN A BMW E21

Hi Pierre, recently i filled my 86 560 SL with Ethanol free fuel and after about 10 miles my car started stalling. Any thoughts or suggestions?

if the fuel accumulator got problem. As a first-aid method, can I jump the fuel pump to make the pump keep pressure the fuel for easy to start the engine?

Seeking to buy a 300 sd from a retired dr. The top coat is in bad shape. My question is how do you offer a fair deal on that car. He said the instrument cluster doesn’t work. The car is just sitting under the tree.