E-Class (W124) 1984-1995: E 260, E 300, E 320, E 420, E 500 (Includes CE, T, TD models)

1991 300 e stalling when engine warm

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Nov 28, 2012 | 09:26 PM
  #1  
phoenix244's Avatar
Thread Starter
Newbie
 
Joined: Nov 2012
Posts: 4
Likes: 0
1991 300e
1991 300 e stalling when engine warm

So it's driven great up until recently, when it began stalling upon acceleration either out of a turn, or from a stop, after driving 10 minuites or so. At this time is chokes, sputters, and stalls when attempting to accelerate. Then may start rough and stall out once more almost immediately, or simply will not start at all. Allow an hour or so to go by, it fires up just fine, and so far....seems to not stall again for awhile.

Where does my diagnosis start? I'm new to MB (and all these relays and sensors I keep reading about), but it seems like a fuel delivery issue. Pump, relay, filter, ovp? Please help me figure this one out as i'm especially hurting these days! Thanks
Reply
Old Nov 29, 2012 | 08:51 AM
  #2  
keith0alan's Avatar
Junior Member
 
Joined: Jan 2012
Posts: 21
Likes: 0
1990 300 te
Check the fuel pressure. There is quite likely an extra port on the CIS you can put a gauge on.
Reply
Old Nov 29, 2012 | 11:11 AM
  #3  
kluvsbenz's Avatar
MBWorld Fanatic!
10 Year Member
 
Joined: Jul 2011
Posts: 1,890
Likes: 6
From: Northeast PA-Poconos
2014 E350, 2006 C350 Sport(made it to 280k, loved it!), 1990 300E
It might be a fuel accumulator or clogged fuel injectors. Try Techron in a few tank fulls to see if this clears it up.
Reply
Old Nov 29, 2012 | 01:16 PM
  #4  
rayhennig's Avatar
Member
 
Joined: Nov 2006
Posts: 117
Likes: 1
300CE 24V Sportline 1991
Originally Posted by phoenix244
Allow an hour or so to go by, it fires up just fine, and so far....seems to not stall again for awhile.

Where does my diagnosis start? I'm new to MB (and all these relays and sensors I keep reading about), but it seems like a fuel delivery issue. Pump, relay, filter, ovp? Please help me figure this one out as i'm especially hurting these days! Thanks
Think of the cheap things first and, with symptoms like that, ignition.

Make sure your HT is first class. All components original MB or Bosch/Beru failing that. In my experience, NOTHING ELSE.

If I were to make a guess for you, I would say rotor arm.

Other than that, HT in general.

Bonne chance.

RayH
Reply
Old Nov 29, 2012 | 08:26 PM
  #5  
phoenix244's Avatar
Thread Starter
Newbie
 
Joined: Nov 2012
Posts: 4
Likes: 0
1991 300e
Thanks for replies. Yes i'll try some techron. And I presume I should change the cap while I change the rotor, yes?

And because I want to understand, why would those things fail after the car warmed up or even intermittently?

Ray, im missing your advice on parts. Do you mean that Bosch IS as acceptable as MB, or no? Also, what is HT?
Reply
Old Nov 30, 2012 | 01:23 AM
  #6  
rayhennig's Avatar
Member
 
Joined: Nov 2006
Posts: 117
Likes: 1
300CE 24V Sportline 1991
Originally Posted by phoenix244
Thanks for replies. Yes i'll try some techron. And I presume I should change the cap while I change the rotor, yes?

And because I want to understand, why would those things fail after the car warmed up or even intermittently?

Ray, im missing your advice on parts. Do you mean that Bosch IS as acceptable as MB, or no? Also, what is HT?
My rotor failed when hot. Let it cool and all was fine for a while.

If the cap, leads or plugs are old, good idea to change 'em.

I mean that Bosch/Beru are fine but MB is best. I have Beru leads and plugs and all seems well.

HT is high tension. High voltage - all the ignition bits from coil to plugs.

R
Reply
Old Nov 30, 2012 | 10:32 AM
  #7  
kluvsbenz's Avatar
MBWorld Fanatic!
10 Year Member
 
Joined: Jul 2011
Posts: 1,890
Likes: 6
From: Northeast PA-Poconos
2014 E350, 2006 C350 Sport(made it to 280k, loved it!), 1990 300E
Originally Posted by phoenix244
Thanks for replies. Yes i'll try some techron. And I presume I should change the cap while I change the rotor, yes?

And because I want to understand, why would those things fail after the car warmed up or even intermittently?

Ray, im missing your advice on parts. Do you mean that Bosch IS as acceptable as MB, or no? Also, what is HT?
I would definitely change the cap and rotor at the same time. That's what I did. Spark plugs as well. My car was riding rough and a few tankfulls(in my case 3) of Techron and it runs a little smoother. My cold start isn't the best although it does turn over. In my case, I may need a fuel accumulator. How are you making out?
Reply
Old Nov 30, 2012 | 09:11 PM
  #8  
lowesguy's Avatar
Junior Member
 
Joined: Nov 2011
Posts: 49
Likes: 0
From: Temecula Ca.
124 92 126 90 R129 91
Also check your rotor mounting bracket for a crack,mine had a crack would expand when warmed,losing ignition,car stalled wouldn't restart until cooled
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-1

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-2

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-3

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-4

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-5

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-6

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-7

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-8

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
story-9

10 Most Reliable Mercedes-Benz Models You Can Buy Used

 Verdad Gallardo
Old Dec 8, 2012 | 05:37 PM
  #9  
phoenix244's Avatar
Thread Starter
Newbie
 
Joined: Nov 2012
Posts: 4
Likes: 0
1991 300e
So I just found some time to delve into this, and thought I would at least do some basic inspection of the ignition system before wrenching, and I fired it up after things looked relatively clean. Sure enough, after 10+ minuite of idling, a "clicking" noise inside the motor began, and it started running rougher. I gave it a little gas and it sputtered then stalled. Is it a cylinder dying when it arms up, or could this be reactive to something simpler?
Reply
Old Dec 8, 2012 | 06:09 PM
  #10  
keith0alan's Avatar
Junior Member
 
Joined: Jan 2012
Posts: 21
Likes: 0
1990 300 te
As my high school shop teacher said, compression, fuel, and ignition are the three things you need. If you can get it to fail consistantly you are way ahead. When it fails pull a plug wire and check for spark. Unless the engine has a very strange problem you are not loosing compression. Check for fuel pressure or take the air cleaner off and when it starts to run bad squirt a little starting fluid into the air intake. If it immediately starts running better you have a fuel problem. Once you determine the basic system with the problem then we can start getting serious.
Reply
Old Nov 18, 2015 | 04:16 PM
  #11  
sayporsha's Avatar
Newbie
 
Joined: Dec 2014
Posts: 3
Likes: 0
SL55 AMG
My 1989 300TE has the same problem. The stalling occurs during warmup, about the time when the engine reaches operating temperature and the system changes the mixture from rich to lean.

This is an intermittent problem but is getting progressively worse. The car will not start for about 30-60 minutes after stalling, but it runs fine after that. Sometimes I keep it from stalling by putting it in neutral when coming to a stop and keeping the RPM above 1,000. If it makes it past the transition from rich to lean, the car runs fine for the rest of the day.

I replaced the Electro Hydraulic Actuator (EHA) hoping that would fix it. The EHA controls the mixture, so I though mine malfunctioned when it got the signal to change from rich to lean. The EHA is not cheap, but I managed to find a good one at a wrecking yard for $10. It does run better now but still stalls.

Last edited by sayporsha; Dec 30, 2015 at 03:04 PM.
Reply
Old Nov 23, 2015 | 04:58 PM
  #12  
RA6523's Avatar
Banned
 
Joined: Sep 2015
Posts: 19
Likes: 0
seeing this revived makes me think of problems I was having - see thread:

https://mbworld.org/forums/e-class-w...ml#post6552682
Reply
Old Dec 2, 2015 | 02:44 PM
  #13  
mazdarati2's Avatar
Newbie
 
Joined: Sep 2015
Posts: 8
Likes: 0
1985 W124 300 E
You can always try to clean your air mass meter.
Reply
Old Dec 3, 2015 | 05:35 PM
  #14  
xclream's Avatar
Junior Member
 
Joined: May 2011
Posts: 41
Likes: 5
R350
Originally Posted by sayporsha
My 1989 300TE had the same problem. I replaced the Electro Hydraulic Actuator (EHA) and that fixed it.

The stalling always occurred during warmup, when the engine reached operating temperature and the system changed the mixture from rich to lean. The EHA controls the mixture, so I'm guessing mine malfunctioned when it got the signal to change from rich to lean.

This was an intermittent problem but got progressively worse. The car would not start for an hour or so after stalling, but it ran fine after that. Several times I kept it from stalling by putting it in neutral when coming to a stop and keeping the RPM above 1,000. If I made it past the transition from rich to lean, the car ran fine for the rest of the day.

The EHA is not cheap, but I managed to find a good one at a wrecking yard for $10.

Sorry to revive an old thread, but when I searched before repairing I learned this is a common problem and a lot of threads had no resolution. I hope this helps.
I have a 91 300E 2.6, and I am experiencing the exact same issue with no way of solving this. I will ask my tech to see if he can check the EHA.

My symptoms sounds the same, cold engine fires right up, drive for 10 - 15 minutes perfectly, then all of a sudden, at red light or stop, engine starts idling really rough, seems like it's choking for air or something, and if light turns green, sometimes I step on the pedal and it feels like it will stall. So usually during this "phase", I put in N and rev it up a bit to keep the engine from stalling or choking.

Strange thing is, after about 10 - 15 minutes of this, it runs perfectly fine, and fine for the remainder of the day.
Reply
Old Aug 15, 2021 | 05:24 PM
  #15  
Mo_haffy's Avatar
Newbie
 
Joined: Aug 2021
Posts: 1
Likes: 0
1989 Mb 300se
300se

Hi.
My 300se doing the exact same thing. Any luck with your problem?

Almost seems to cough, splutter and stall at about 10 minutes when engine just about warms up.

Give it about an hour to rest, it starts up and goes as if nothing was wrong.

Help....

Originally Posted by phoenix244
So it's driven great up until recently, when it began stalling upon acceleration either out of a turn, or from a stop, after driving 10 minuites or so. At this time is chokes, sputters, and stalls when attempting to accelerate. Then may start rough and stall out once more almost immediately, or simply will not start at all. Allow an hour or so to go by, it fires up just fine, and so far....seems to not stall again for awhile.

Where does my diagnosis start? I'm new to MB (and all these relays and sensors I keep reading about), but it seems like a fuel delivery issue. Pump, relay, filter, ovp? Please help me figure this one out as i'm especially hurting these days! Thanks
Reply
Old Aug 15, 2021 | 06:37 PM
  #16  
lowesguy's Avatar
Junior Member
 
Joined: Nov 2011
Posts: 49
Likes: 0
From: Temecula Ca.
124 92 126 90 R129 91
On my 1990 300SE after replacing a few parts, it turned out to be EHA valve, expensive but the car ran like new, never stalled again, inspect bottom of valve with a small mirror and flashlight, if you see remnants of fuel ,its leaking when you drive.
Reply
Old Mar 3, 2022 | 12:11 PM
  #17  
Geewizzpip's Avatar
Newbie
 
Joined: Mar 2022
Posts: 1
Likes: 0
300 CE
Originally Posted by phoenix244
So it's driven great up until recently, when it began stalling upon acceleration either out of a turn, or from a stop, after driving 10 minuites or so. At this time is chokes, sputters, and stalls when attempting to accelerate. Then may start rough and stall out once more almost immediately, or simply will not start at all. Allow an hour or so to go by, it fires up just fine, and so far....seems to not stall again for awhile.

Where does my diagnosis start? I'm new to MB (and all these relays and sensors I keep reading about), but it seems like a fuel delivery issue. Pump, relay, filter, ovp? Please help me figure this one out as i'm especially hurting these days! Thanks
Hi. I had this problem with my 300CE. It would start perfectly and then just cough and splutter after 15 minutes and then refuse to start, as if there was a spark problem. After I tried everything from new dizzy and leads to new coil with no change. Then I took the air cleaner off to look for the crank sensor. I couldn't reach it so I just started the car without the air cleaner. It kept running!! So I put the air cleaner back on and disconnected the rocker breather. It now runs perfectly and hasn't stalled since. My only thought is that after 250,000 miles maybe the air from the rocker cover is too oily when the engine is warm and that was either confusing the fuel injection (the little tube from the rocker cover pipe) or it was just bad air going straight into the fuel injection system. Whatever it was it seems to work. So before you spend any money just disconnect the breather!
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 04:58 PM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE