SL/R107: Won't idle more than a few minutes

Reply Subscribe

Thread Tools

Search this Thread

Rate Thread

Feb 11, 2019 | 09:40 PM

Riggmaster

Thread Starter

Newbie

Joined: Oct 2017

Posts: 3

Likes: 0

From: Ewa Beach, Hawaii

1975 450SL, 1982 380SL, 1995 SL320, 2004 SL500, 2012 C250

Won't idle more than a few minutes

Have a 1982 380SL I picked up after having set around for several years. After finally getting it started, new gas, plugs, distributor cap and wires, it will start, but then stall.

Car starts, idles, fuel pump makes a loud buzzing type sound, the engine begins to stumble then stalls. It will stay running if I hold the accelerator through its "rough surging" periods. These rough periods last about 15-20 seconds, then it will idle by itself again until the next rough period. This happens even if I bypass the fuel pump relay.

New fuel pump, fuel filter, accumulator, warm up regulator. Rebuilt fuel distributor. All fuel lines, both to distributor and return lines, have been blown with compressed air to ensure no blockage.

I've spent close to a year on this issue, even with the help of mechanic friends. I'm lost.

Last edited by Riggmaster; Feb 11, 2019 at 09:45 PM. Reason: Typo

Apr 21, 2019 | 07:19 AM

FRANK N

Newbie

Joined: Feb 2019

Posts: 6

Likes: 0

From: NC, USA

1987 560SL, 2007 SL550, 2012 E350, 2010 c300

87 560Sl stalling when reaching operating temperature

I have 1987 560sl, 72k, perfectly maintained. I have a stalling issue. from a cold start the card idles perfectly (or runs) until reaching operating temp (80c) at which time it stops and will not restart until the car sits several hours and is completely cold again. Replaced: fuel pump relay, distributor cap, rotor, crank position sensor...no change. It appears to be losing spark at the time time it shuts off....STUMPED. Any help/suggestions appreciated
Thanks fellow Benz lovers.

Apr 21, 2019 | 01:00 PM

Riggmaster

Thread Starter

Newbie

Joined: Oct 2017

Posts: 3

Likes: 0

From: Ewa Beach, Hawaii

1975 450SL, 1982 380SL, 1995 SL320, 2004 SL500, 2012 C250

Quote:

Originally Posted by FRANK N

My problem with not running, was a blocked return tube going into the fuel tank. After I’ve solved that, I could not start it at operating temperature until after a few hours also. I was told to change the crank position sensor. Amazingly, that did the trick.

Apr 21, 2019 | 01:35 PM

FRANK N

Newbie

Joined: Feb 2019

Posts: 6

Likes: 0

From: NC, USA

1987 560SL, 2007 SL550, 2012 E350, 2010 c300

new Ccrank Pos Sensor didn't do the trick...now looking at EZL ignition control...ufortunately

Apr 21, 2019 | 01:49 PM

Riggmaster

Thread Starter

Newbie

Joined: Oct 2017

Posts: 3

Likes: 0

From: Ewa Beach, Hawaii

1975 450SL, 1982 380SL, 1995 SL320, 2004 SL500, 2012 C250

Good luck

Apr 23, 2019 | 08:22 PM

myway

Senior Member

Joined: Jan 2010

Posts: 330

Likes: 26

From: Middle of Nowhere, USA

450SL

Quote:

Originally Posted by Riggmaster

On an '82 380SL? The only thing close to a CPS is at the front of the engine connected to the diagnostic socket. It doesn't have anything to do with running.

Jun 27, 2020 | 05:22 PM

FRANK N

Newbie

Joined: Feb 2019

Posts: 6

Likes: 0

From: NC, USA

1987 560SL, 2007 SL550, 2012 E350, 2010 c300

Had the new Crank Position Sensor tested and it was faulty. Ordered a replacement from Germany and it solved the start/stall issue, but immediately developed a miss/sputter after driving for 45 minutes or so. It would run perfectly around town or on the road for about 45 minutes after a cold start. Indy was stumped as well as every mechanic, website I spoke with. Today I adjusted the fuel/air mix 1/4 turn clockwise (Rich) and drove it non-stop for 2 sessions of 70 miles each.... no miss, no sputter.
Before adjusting air/fuel I checked my exhaust to see if the inside of the pipes were oily, indicating rich condition and found them to be dry, non-sooty. Increasing the richness has made it smooth as silk.