Mervyn,

This is why I joined this forum: all of the posts I have read (on my topic and others) are to-the-point and helpful.

I have a very comprehensive list amassed, so rest assured that I will discuss everything with my technician, ASAP.

I will tackle the easier (and cheaper) fixes, first; I will let everyone know the results (though it may be a few weeks from now).

With sincere thanks,

Mervyn:

I have scheduled service for the morning of WED 21MAR01 to
replace my distributor cap & rotor, spark plugs, and spark plug wires.

I will let everyone know the results.

Thank you,

Hi Scott, that's the way to go. Replace the "perishables" first. That is my usual way of diagnosing a "phantom" problem and save the bucks for later.

Just one more note: try to see if you can get hold of another ignition control module (in perfect working condition) from say, a friend or the mechanic, and try it on your car. That'll save a some risky bucks, and if the stalling problem disappears thereafter, you know what you're after! Thats what I did, and I feel very comfortable that way.

Let us know, good luck!

Mervyn
W126 (280SEL)
Singapore

Mervyn:

Your idea sounds wise; I will endeavor to do so.
Thank you very much for your thoughts.

I wonder: are there any possible risks of "mixing" firmware versions between production years (i.e. - an LH unit from a 1994 vehicle in my 1993 vehicle)?

Anyone have any experience with this?

You can use the module from a 400E as well, I know, because I put a 1992 400E module in my car to make it pass emissions (I have a superchip).

David Hendy
'92 500E 65k miles

Thanks for the update; I have asked my technician to do so!

All:

I just picked up my 500E from my local dealership.

My cooling system had a bad (leaking) hose, so it was replaced. In the process, I my technician added Watter Wetter to my coolant bottle/radiator.

I must say, the car does seem to run from 5 to 15 degrees (F) cooler (8 to 10 degrees cooler, I would say, on average). I determined this during the course of my approximate 30 mile drive home, at speeds ranging from bumper-to-bumper (0 to 5MPH) all the way up to... the posted speed limit (of course): 65MPH.

For those who are skeptical, myself (once) included, the proof is in the pudding - and in my cooling system, now.

Just my $0.02.

My second wiring harness will not be replaced until the end of next week; the part is still en route from Germany.

As promised, I will post pictures of my car NLT 1800 tomorrow, SAT 17MAR01.

Drive safely,

My 92 has developed an intermittent rough idle/almost stall, and I will be very interested in how things work out with chip replacement etc.
The last time I had a car do this to me it was a defctive sparkplug, but there is no apparent cause for current symptoms.
Best wishes

__________________
John
92 500e, 85k, silver/gray,all stock.
96 Club Wagon,Hypertech chipped( College Hauler)
97 320 SL 50k
1980 BMW e21 323 Baur conv.
1990 300GE 99k

John:

I will let everyone know how my car is running by THU 22MAR01; I will have replaced all my plugs, plug wiring, and cap/rotors, by then.

Kind regards,

All:

While I am sorry to say that the replacement of all my ignition wiring, distributor caps and rotors, and (Bosch,m stock) spark plugs did *NOT* solve my stalling problem, I am nonetheless happy that I have one less possible problem area to scrutize.

500E/E500 owners may be interested to note that the total cost for the above job (parts & labor), here in Northern California, was: $1325.00
(approximately $900.00 in parts, $350.00 in labor, and $75.00 tax).

I will replace my charging system wiring harness (under warranty), tomorrow morning: I will post the results of my
(stalling) tests after I have picked up and tested my vehicle.

Thank you,

Scott,

Since the EA been replaced and the acceleartor linkage has been adjusted (what difference did that make?), have you replaced the PAD chip with the original eprom?

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

Visit my Mercedes Web Page

Jim:

Indeed, I have; nothing seems to fix this elusive problem.

The consensus seems to be that there is an electrical short/fray somewhere.

I appreciate your input, though. Please stand by as the saga unfolds...

Kind regards,

All:

I am sorry to report that, even after all wiring harnesses, spark plugs, ignition wires, caps, and rotors have been replaced in my 1993 500E, my stalling problem STILL exists.

* SIGH *

My dealership is being VERY cool, though, and we will tackle the problem, in earnest, in a few weeks.

Please follow this thread (a-la Theseus), for more updates.

On a lighter note, did I mention that the RENNtech 1st gear start valve body is a BLAST??!! If you install one in your 500E/E500, I highly advise an ASR defeat relay, also; without one, your ASR light will be in "full auto" mode...

: )

Have a nice weekend,

Scott,

Mervyn asked whether the Ignition Control Module (ICM) was replaced. I may have missed that answer that in all of the voluminous replies to date but would like to know.

In my car (S500 cpe), the check engine lite illuminated and per the Diag module (N59), the trouble said "CAN communications ineffective" and "AIR faulty". Also reading the DI (N1/3) module, said "CKP (L5) sensor bad". This was an ACTIVE fault, so it showed up as soon as the car was powered. Also this fault, immediately lites the MIL.

The bad element was the ICM, causing all the other failures. I replaced it (after searching here, ParTrackers, and some others) with part from a Brooklyn NY junk yard for $200 plus shipping. New part is $1113 retail.

My reasoning was this: L5 was good by ohmmeter measurements, if not the car wouldn't start! The car used more gas than it should, but other than the faults, it ran just fine.

After installing the new ICM, everthing worked just fine. The CAN and L5 faults were caused by the ICM. The gas milage went up to 15+ mpg city. The sw date on my old part was 5.93, the new one 7.95.

My point to you is that idle speed control is ALSO determined by the ICM and should be around 550 - 750 depending on IAT and ECT sensor temps, etc. Maybe it's worth a try.

Am monitoring this for a conclusion.

[Edited by JimF on 03-24-2001 at 02:11 AM]

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

Visit my Mercedes Web Page

Jim:

Your post was very specific; thank you VERY much for your detailed advice.

I will endeavor to replace my ICM; I have three questions, please:

1.) How did you determine the version of your ICM firmware?
2.) How did you specify the new part/firmware revision?
{For example, did you request that the salvage yard send
you an "ICM, firmware version 7.95 ?"}
3.) Is the ICM similar to the LH-unit, in that it may be
taken apart (opened up) - revealing a socketed
(insert-mount) EPROM? If so, I can clone a good chip,
easliy, with my device programmer (on my PC).

RSVP / Again, THANK YOU for your input!

Very kind regards,