1993 400e runs rough at temp, fine when cold
 

My 400e is misbehaving. It sat for a few years awaiting a new radiator and fan clutch. Those since have been installed, as was a new headliner and sunroof repaired.
But now, after she warms up, she stumbles and is bogged down.
runs great from the start until approx 60C is reached.
Upper harness replaced by PO.
Pulled codes from the push button LED diagnostic port and got code 17 - data exchange fault between individual control module

So I did some research and came across this http://www.peachparts.com/shopforum/tech-help/42411-fault-code-17-data-exchange-problem-dealer-b-s.html

So I disconnected the battery and pulled the module with the fuses to look for the TWO WIDE pins. Could find only one wide pin, so I reinserted the module and reconnected the battery.

The I pulled other codes from socket 4, 8, 17 all with 1 blink (which means OK) But socket 7 gave me 11 blinks - Fuel safety shut-off to LH-SFI control module - and socket 19 now didn't blink at all.

now I'm at a loss.

Think I got her figured out (fingers crossed)
I had replaced the ECT sensor because a) it threw a code and b) measuring resistance showed an open.
Well with the bad ECT sensor the self-adaptive feature changed the fuel/air ratio.
Without resetting this feature, the car thought it should change the air/fuel mixture to some not-to-nice setting.
I reset the self-adaptive feature to mean value by pressing the button on my impulse counter for 8 seconds while the test lead was in socket 4 after a reading of one blink.
Drove the car approx 7 miles without a hiccup.
Turned the car off. Then the check engine light came on. I turned the ignition on (without starting the car) and happened again. I then started the car and let it idle for a few seconds and after turning off the car, the CEL stayed off.
Waiting a few minutes, drove the car 2 miles no problems.
Turned the car off waited about 15 minutes, drove a couple miles, still no problem.
So either it's fixed, or it's intermittent. I'm hoping it's the former as opposed to the later.
Time will tell.

No luck,

Before I begin, the battery was discharged over the course of 2 days. I know the battery holds a charge, as it was 68% charged after sitting
in the garage for several months.

Another interesting thing, last time I test drove it (10 miles) the headlights were on while driving (it was night time)

Drove today, got up to temp. running fine. Turned her off for about 5 minutes, on restart problems reappeared immediately.
She's bogged down, throttle response is like a 4 cyl press the accelerator pedal half way down to get any movement.
High sulfur smell (rotten egg) from exhaust.
Have not pulled codes (again) yet.

So let's see what potentially might be wrong.

1) alternator noisy (headlights cut down on the noise)
2) I need to let her cool and see if she runs good for more than ten miles and see if it's only on restart that she misbehaves.

Any other suggestions?

here's the latest,,,
Didn't seem to misbehave, but not running right, didn't downshift one time when I thought she should have,,,
Pullld codes socket 7 showed 11 blinks and socket 17 showed 28 blinks.
socket 17 fault = Electronic accelerator control module/idle speed control data exchange fault

Having difficult time finding socket 7 codes, as the manual shows no 38 PIN DIAGNOSTIC for socket 7 in a W124 w/o ASR

Ready to pull my hair out.

You may be over analyzing this. From my experience, 90% of the time when a m119 missfires after up to temp, it's the distributor caps. Remove them and check for arcing marks on the inside. If they're new, disregard my comment.

Thanks I'll take a look at the distributor caps tomorrow

That was going to be my suggestion as well.

The battery drain is a mystery though. It seems rather common on the .034 cars though since there is a member on BW who also has the same issue and the first 92 400E I looked at had it as well. I didn't buy that car and the other member installed a quick disconnect for the battery so I cant really help on the battery drain.

mespe, remove the voltage regulator from the back of the alternator and check the length of the brushes. If they are worn down to short nubs, replace the voltage regulator which should ensure that the battery recharges as you drive.

Thanks for the input fellow forum members.
I pulled one of the distributor caps off and, well, to be honest, I don't know how the car even ran,,,
I suppose all the extra arcing may have affected the voltage system, throwing spikes and what nots with electrons flying around.
Even being as frugal as I am, I just couldn't (wouldn't) steel wool the contacts and test again,,,
I cannot believe that it's going to cost me $219 to replace the rotor and caps on this car, had I known the cost when I parted out that S500, I probably would have kept the caps and rotors from that beast,,,
Now just waiting for the parts to arrive from this forum's host.

There are also some caps that are behind the rotors that can collect moisture. Sometimes you can get away with simply cleaning them and sometimes they need replacement.

When you write "caps" do you mean there are capacitors behind the rotor? Or did you mean the distributor cap?

It's the insulator caps behind the rotor. Sometimes there is moisture and sometimes there are hairline cracks which can cause the spark to ground.

http://www.w124performance.com/docs/mb/other/ignition_misfiring_STAR.pdf

If new caps and rotors do not fix it, I would be eyeballing the throttle body (ETA, I think is the acronym they use) with great suspicion. You can try cleaning the wire in the O2 sensor with cleaner too, while you have the air box off - just to eliminate that off of your extensive list of things to check. Good luck!

I cleaned the one distributor cap and rotor (rotor required some filing). The other dist cap looked OK.
While I'm waiting for the parts to arrive from our forum host, I thought that I might go for a test drive.
Still getting 17 blinks on the DM
"Data exchange fault between individual control module"
I fail to see how a bad rotor or dist cap could cause that type of error.
It's a data error
I pulled codes from all other sockets 4, 7, 8, 17 and all OK.
I willing to bet the car that when I replace the dist caps and rotors, I'll still get that fault. Heck, Even if I replace the plugs, wires etc I'll still get that fault. Car runs good after cleaning the rotor& cap, I can FEEL more power (until closed loop kicks in perhaps).

I NEED HELP WITH 17 BLINKS!!!

I found this little better DTC code explanation,,,

Data exchange (CAN) fault between engine control module, ignition control module or electronic accelerator/cruise control module. Bank 1

so now to locate a wiring diagram