About a month ago, my (so far) completely dependable 1996 140 coupe stopped running at a light about 2 minutes after starting after sitting for two hours. No warning, no stumbling, just died, leaving all the warning lights on, like the ignition had just been switched on. About ten minutes later, again at a light, it almost died, but then did a little surge and stayed running.

I sought local advice, looked at the TSB's, did a Search and replaced the crank position sensor and added a .5 mm shim as advised.

The problem went away for a couple of weeks, and then it happened again just as I was coming to a stop. More consultation, and advice to try a different key. I also had all of the codes pulled from all of the modules, and nothing relevant showed up.

OK, so with a different, barely used key, the problem did not recur for a few days. Then, a couple of nights ago, driving at 25-30 mph, I could feel the engine lose power, twice, for less than a second each time.

The only other weirdness with the car is occasional ASR/ABS lights that go out when the ignition is cycled, but this did not happen in any of the recent dieing episodes.

I am considering a fuel pump relay. The fuel pump was replaced about 18 months ago and has about 8K miles on it.

So any other suggestions on what to test or what to try? This is a rather large car that you don't want to die on you in traffic.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Bump!

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

What were the codes??

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

I don't have the print-out with me, but as I recall:

- the window controller thought the switch direction was backwards (not true)
- a couple of "implausible" readings from one wheel sensor
- one other "implausible" from the transmission gear selection

The tech said they see this random stuff all the time, and none of it had any relevance to the stalling problem. It's not leaving any tracks.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

The VSS (vehicle speed sensor) is very important . . . I'd re-think that conclusion. . .

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

OK, I can see the VSS code being related to the occasional ABS/ASR lights.

What is your hypothesis about the relationship to the engine suddenly shutting down?

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Here are the codes:

HE1R
P1519 Right adjustable camshaft timing logic chain

ASR
C1101 RPM sensor RF -000 L6/2 Wire

ETC.6
114 Occasionally Selector lever implausible
120 Occasionally RF VSS from engine management implausible, CAN
126 Occasionally Altitude correction from engine management implausible, CAN

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

At this point, I don't think it's valid. . . .

Since you replaced the L5 (cksft sensor), it still could be electrical . . intermittant coil?? But the fuel relay is probably as good a choice as any other.

Have you checked the fuses in the Base Module . . maybe replace them. The Base Module is the "OVP" of W140 cars. . .

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Hook up a fuel pressure gauge and go for a drive and watch fuel pressure when it dies.

__________________


1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350

The hose came in today, so here I go.

Attached Thumbnails

   

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

I have been driving around for a couple of days with the gauge. The pressure seems perfect.

But it did die on me at a light today. No miss, no warning, just died. The pressure was sitting at about 3.2 bar and went up to 3.8 as the car died. Then dropped back to 3.2 with the engine off. Car restarted easily, drove off fine.

The surge and the die happened simultaneously.

I have noticed that if you simply shut the ignition off, which it seems would simulate the fuel pump stopping, the pressure stays at about 3.2 and drops imperceptibly to about .8 bar overnight.

Does this ring a bell with anyone?

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

. . . it's not fuel related . . . I would bet?? What do you think?>

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Agreed. More likely ignition/electrical.

I think the quick jump in fuel pressure is happening beceause the injectors are shutting down a fraction of a second before the fuel pump is cut off. Like the ECM is doing it for some reason, or the ECM or some other critical piece is losing power.

I did plug into the OBD port and the sensor plots and other readings looked normal. The only oddity was that the long-term fuel trim was 5.5% and 6.0% bank 1/bank 2.

Whatever it is, it's starting to happen more often.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

I had a talk last night with my ultimate resource, a tech team lead at the area's largest dealership. He suggested first checking the basics: battery charging, grounds, clean leads, etc.

Then he mentioned three possible causes: bad base moduel, bad ECM, and the trans module locking up the torque converter and killing the engine. He also said to check the harnesses for oil "wicking" from the transmission and from the cam ajdusters.

So I took a look at the base module and noticed some oil in the bottom of the relay compartment. To get a better look, I unhooked the trans module and noticed oil around the connecting pins. Then I removed the trans module, and trans fluid spilled out of it as I turned it. I put it in a pan, and I would say a cup of fluid ran out.

So my working theory is that being full of oil caused the module to malfunction and occasionally lock up the TC.

I will try to get the case off try to clean it up and see what that does for the stalling problem.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Hey there, been following your exploits on Benzworld. That base/trans module you talk about. Is it stuck to the bottom of the tranny?
Do you have any part numbers or pictures to identify which is which?

Just had a thought though, I've had an episode of this at over 2000RPM, would the Torque converter not already be fully locked up at this engine speed?
As an aside, I've noticed my engine speed when idling, (car in gear), is lower than normal. Last but not least it has performed the cut out thing while sitting in neutral too, so is the tx a red herring? (Start your car and just leave it sitting there idling in neutral and see if it happens).
Don't know really if these are just coincidence but they all came about at the same time.

Couple of pics added too. Found the 38 pin connector at last. For some reason I always assumed it was on the other side of the engine and could obviously never find it there. In the pic next to it there is a bracket. Is this where where the LED blinker might usually sit on US spec cars?
The fuse box is pictured also, can see none of the expected modules there, (base module).

Any help is much appreciated.

Attached Thumbnails