I've notice lately that, when cold, the E420 just doesn't want to go - I feel safer stomping on the accel pedal on the 300D when it is cold, than with the 420....at least I know the 300D won't stall.

OK....When cold, I step on the "gas" to get into traffic, and not much happens....either it brumbles* and then finally catches itself, or it nearly stalls (I had it stall once) and I let of the gas quickly, so it won't stall - then try it again.
If this thing had a carb, I'd say the accelerator pump is shot.

O2 sensor?

Thank you for your thoughts!

-Larry


*"brumble": a low rumble ...the kind you hear when a motor is bogging - Secondaries are open, but it just kinda goes baaaaaaaah.

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

More like a bad mass air flow sensor.... ALSO the distributor caps could be gummed-up.

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Thanks for the reply Doc,
The air mass sensor was replaced within the 6 months or so. I will check the caps for wear. (is that what you mean by "gummed up" - wear & carbon streaks?)

thanks!

-Larry

PS: If it's the air mass sensor, why would this manifest itself only when cold? - because the wire isn't getting hot fast enough?

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

corrosion better known as the "greed gook"

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Here are pics of the caps and one of the rotor. They show some wear/corrosion, but I don't think it's the worst anybody has ever seen. I did note small hairline cracks near two of the posts on the pass. side cap.

For the longest time, I had the CEL on for a mundane code (something about module box being too warm) - naturally, if the light is already on, you're not going to see any "new" codes. Well, sure as S, I had codes 10 & 17.

Rassinfrassinfrikkinfrakken

I've reset the codes, and will see which one pops up first.

Something I noticed: When accelerating moderately, once I get past a certain RPM range, the car suddenly finds an extra set of balls, and really gets going.

Attached Thumbnails

     

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

I know when my 190e was doing that exact same thing, only when cold, I changed the altitude sensor and that was all it needed.

Larry,

Does your E420 surge up and down then almost stalls while you are accelerating? Do you notice the RPMs surges up and down as if the engine can not find an idle? If so I suggest you check your Ignition coils, it could be possible that one of the coils are going out. Worse case is the Ignition Module is starting to fail . If possible try to swap a good Ignition Module with someone to see if that is your problem. On my E420 the Ignition Module finally put me down and I had spent months trying to solve that problem. I at first thought it was my Electronic Throttle Actuator "ETA" (M16/1). There is not an exact code to say the Ignition Module is going out, that is why I suggest trying to swap out with a friend to see if that is the problem.

You can also try to see if you can scan the Ignition Module to get it to produce some type of codes. My Ignition Module did not produce any codes that would lead me to any error because it was cool and it only gave me a good reading. It was not until I tried to start the engine over and over again and the Ignition Module heated up and finally gave me false reading. Since your engine still starts up and run, allow your module to get heated up then scan the codes and see if you get any false codes.

I hope this helps.


Check JimF's site
http://pages.prodigy.net/jforgione/MB_DI.html
http://pages.prodigy.net/jforgione/MB_EA.html

DRich,

Thanks for the reply.
When accelerating, it doesn't really surge per se, it just seems to take a long time to decide what mixture it wants/needs, and then hauls butt.
The ignition module is only 2 years old, as is at least 1 coil (don't remember if both were replaced).
The majority of the trouble is when the car is cold - once it is warm, there is just a minor hesitation most of the time.

It idles fine hot or cold. It is more difficult to start cold - longer cranking time - like I wrote in an earlier post, if it had a carb, I'd say the accelerator pump was shot. *sigh*

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Code 10 popped up first, yesterday.

I don't know if it's me or not, but it seems to run better when the codes are re-set. Must be some kind of placebo effect.

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

So, I did some investigating, and using a home made code reader tool, I found the following:

Pin 5 gives me Code 10 (CTP (idle) recognition from EA/CC/ISC control module (N4/1), short circuit) (from JimF's site)
Pin 6 gives me Code 13 & 30 (Stop Lamp switch & CAN data line to EA/CC/ISC module (N4/1) (from JimF's site) - Note: the stop lamp switch was replaced a couple of years ago - is this a leftover code?

Pin 7 gives me Code 6 (Starter lock-out/backup lamp switch (S16/3)) (from JimF's site) is a back out lamp broken? wouldn't the dash lamp indicate this?

Pin 17 gives me Code 8 Haven't the foggiest what this means.


What I am wondering is, is it one item that is malfunctioning and causing a cascade effect?

Thanks!!

-Larry

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Apparently while interrogating the different pins, I shorted fuse #9 - the biggest indicator was that the climate control quit, as well as the radio. At first, I paid no attention to it, figuring I must have re=set something and that all would be well upon start up.

Boy, was I wrong.

I had to have it towed this morning. I just came from the shop, and they didn't have time to look at it much. While I was there, I fiddled around with it, and discovered the LED to be dimly lit. So, I checked the fuses, and found #9 blown - replaced it and the LED went dark; the LED also didn't give me any codes.

However it runs like crap. Before I replaced the fuse, the idle hunted big time. After the fuse replacement, it ran a little better (maybe placebo effect) but had to be coaxed gently to higher rev's or else it would bog down (like when you step on a 4bbl and there is no fuel for the secondaries - sounds like a "Woooof" but without the "f" sound)
The exhaust also smelled rich.

Yeah, I kicked the car in the tire
(I didn't dare kick it in the bumper - probably break something)

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Larry,

I had all those same codes when I was trying to hunt down the problem with my E420. I replace all those items that you got codes for including the ETA and still the M119 would not run. What does your hot wire on the air mass look like, is the wire intact and is all connected. My problem was the Ignition module, but you say yours is only two years old. What about you LH-SFI Module this module controls your air/fuel mixture. The LH module also harvest the chip. Another item that comes to mine is the Crank sensor on the flywheel. From what I have heard those sensor hardly never go bad.

http://pages.prodigy.net/jforgione/MB_SFI.html

Do you have the repair manual on cd so that you can get the wiring diagram? I will dig mine up and try to help you hunt down this problem. Keep us posted on your progress.

DRich,

Thanks for your reply!

The air mass sensor is less than a year old - It was new (not rebuilt) so, I'm leaning away from that being the problem.

Not sure about the LH module itself (Can I borrow yours? )

I spoke briefly with the tech today, he told me what I already knew, which is that there is no CAN communication. Too bad it doesn't get more specific than that (ie: the CAN is not talking with the LH module). Maybe it does get more specific, I just don't know it. I still don't know what Code 8 on Pin 17 is either.

I'm not trying to take the work away from my tech, I just want to be able to quickly point him in the right direction (he is trying to squeeze me in as it is).

PS the LH module does not appear to be cheap either.

Thanks again!

-Larry

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Larry,

Check your email I have a extra LH module.

The starter lock-out switch is the first thing that is going to be replaced (Pin 7, Code 6). Then we'll see what is left over.

Apparently, when I blew fuse #9, I also blew a fuse on the base module.

OR - the fuse on the base module blew on its own, and I blew the #9 fuse on my own.

Still no clue as to what Code 8 on Pin 17 is.

I could just save myself a lot of trouble and throw some Holy Water on it - if it catches fire, I'll know for sure what the problem is.

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D