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

help! my 88 260e runs for 4sec then dies

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Sep 27, 2008 | 01:19 AM
  #1  
m.j.t's Avatar
Thread Starter
Newbie
 
Joined: Sep 2008
Posts: 5
Likes: 0
1988 260e
help! my 88 260e runs for 4sec then dies

I ve had this car for over 250,000 miles and with no problems then on my way to work it dies. It starts right up runs ok for 4 seconds then dies, I cant find a wiring schematic for the car, I was thinking maybe a senser of some type is shutting it down. I just don't know any info would be greatly appreciated. thank you michael
Reply
Old Sep 27, 2008 | 02:35 AM
  #2  
ohlord's Avatar
MBWorld Fanatic!
 
Joined: Apr 2007
Posts: 6,171
Likes: 16
300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
Have

you checked the fuel pump,the fuel pump relay,and the fuel filter?
After that
http://www.autohausaz.com/search/pro...ition%20Sensor
if bad,not good,easy diy.

where are you located?If you are not a diy type of owner before you throw a bunch of parts at it,it might be a good idea to have someone with a tester check the sensor values.
Reply
Old Sep 27, 2008 | 11:52 AM
  #3  
RBYCC's Avatar
MBWorld Fanatic!
 
Joined: May 2005
Posts: 2,494
Likes: 17
From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
Originally Posted by m.j.t
I ve had this car for over 250,000 miles and with no problems then on my way to work it dies. It starts right up runs ok for 4 seconds then dies, I cant find a wiring schematic for the car, I was thinking maybe a senser of some type is shutting it down. I just don't know any info would be greatly appreciated. thank you michael
If you do not get a speed signal from the tach to the fuel pump relay within a few seconds after starting, the engine will shut down.

This is a safety circuit designed to prevent fuel from being pumped into an engine that is not running...i.e. broken fuel line
Reply
Old Sep 27, 2008 | 08:48 PM
  #4  
m.j.t's Avatar
Thread Starter
Newbie
 
Joined: Sep 2008
Posts: 5
Likes: 0
1988 260e
Thats just what I thought, I,m going to work on it today thank you for the info and taking the time to help. I'll bet that twin turbo must be a blast to drive. Michael
Reply
Old Sep 28, 2008 | 08:58 AM
  #5  
RBYCC's Avatar
MBWorld Fanatic!
 
Joined: May 2005
Posts: 2,494
Likes: 17
From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
Originally Posted by m.j.t
Thats just what I thought, I,m going to work on it today thank you for the info and taking the time to help. I'll bet that twin turbo must be a blast to drive. Michael

TT on a M103-12V is surprisingly fast, even at 7psi boost

Below is a wiring diagram with the tach/speed signal highlighted.
More then likely the problem is the fuel pump relay if you have the speed signal.
If you don't have the speed signal it could be as basic as the crank sensor or a problem with your KE control.

Start with the basics as it's the least expensive path

Reply
Old Oct 1, 2008 | 01:56 AM
  #6  
m.j.t's Avatar
Thread Starter
Newbie
 
Joined: Sep 2008
Posts: 5
Likes: 0
1988 260e
Thanx for the wiring diagram, I was having trouble getting a copy of it. Well I hooked a meter to the pumps and started the car and held 12 volts till after it died, so I guess the relay is doing its job. It dies so solid I can't believe it could be a filter. But after tearing the dash board apart to check the wire on the back of the tack{prior to getting the diagram} I've been humbled and Im getting a filter and a new pressure. back to basics good advice thanx again Michael
Reply
Old Oct 1, 2008 | 02:07 AM
  #7  
YNVDIZW124's Avatar
MBWorld Fanatic!
 
Joined: Apr 2005
Posts: 2,849
Likes: 3
From: Long Beach, Ca
lots of cars
Two questions, are you getting spark? are you getting fuel? check your fuel pump relay. Your can make your car run without the computer but i'll run very rich. You have to follow a process when you check these things because if you move one thing then another you'll never get back to what it was before. One of my mustangs didn't want to start so i rebuilt the car and changed the fuel pump and problem solved. It's not that easy with our cars but it's not impossible either.
Reply
Old Oct 1, 2008 | 07:47 AM
  #8  
RBYCC's Avatar
MBWorld Fanatic!
 
Joined: May 2005
Posts: 2,494
Likes: 17
From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
Originally Posted by m.j.t
Thanx for the wiring diagram, I was having trouble getting a copy of it. Well I hooked a meter to the pumps and started the car and held 12 volts till after it died, so I guess the relay is doing its job. It dies so solid I can't believe it could be a filter. But after tearing the dash board apart to check the wire on the back of the tack{prior to getting the diagram} I've been humbled and Im getting a filter and a new pressure. back to basics good advice thanx again Michael
Reverse your logic a bit...


Bypass the feed from the relay to the fuel pump with a jumper so you have voltage direct to the pump.
In essence taking this function of the relay out of the circuit.
Monitor the speed signal to see if it maintains beyond a few seconds.
If it does then you proved this input valid.
Possibility then that it is a defective fuel pump relay which is dropping out in spite of the available speed signal.
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 Oct 1, 2008 | 02:59 PM
  #9  
YNVDIZW124's Avatar
MBWorld Fanatic!
 
Joined: Apr 2005
Posts: 2,849
Likes: 3
From: Long Beach, Ca
lots of cars
I have like 4 fuel pump relays btw....
Reply
Old Oct 4, 2008 | 03:52 PM
  #10  
m.j.t's Avatar
Thread Starter
Newbie
 
Joined: Sep 2008
Posts: 5
Likes: 0
1988 260e
Unhappy

I ran jumpers from the pump to a meter inside the car, started the car, it held voltage for a couple of seconds after the car died, so that clears the relay? whats the week link in the ignition?
Reply
Old Oct 4, 2008 | 11:20 PM
  #11  
RBYCC's Avatar
MBWorld Fanatic!
 
Joined: May 2005
Posts: 2,494
Likes: 17
From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
Originally Posted by m.j.t
I ran jumpers from the pump to a meter inside the car, started the car, it held voltage for a couple of seconds after the car died, so that clears the relay? whats the week link in the ignition?
Maintain the voltage on the pump so it runs and the engine should continue to run.
If you are able to read the speed signal at the relay while the engine continues to run, then replace the relay as it probably is dropping out when it should be holding.

If you don't read the speed signal, then check the crank sensor where the signal originates.
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 01:44 AM.

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