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2009 ML320 & 1984 190D
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229 Posts
Discussion Starter #1
M103 2.6L in a CA version 1990 190E,with the 16pin diagnostic.
Thought I would get a larger pool of input here!

Car failed smog ... twice... trying to figure out whats wrong.
Failed on HC at idle last time.
My son says he thinks it feels sluggish off idle on acceleration.
Duty cycle is fluctuating fine and set around 50%.
Engine starts first time and feels/runs great.

My question is this:

Key on engine off... I get 69.9% from the X11 using my Sears DMM.
Moving the throttle mechanisim a bit of idle I hear the little switch click and then a little more I see it increase to 89.9%.
Full throttle changes the reading agian to 79.9%.

Depressing the Throttle plate does not change anything tho... and I thought it should....

Help!
 

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1999 E320, 2000 E320, 2003 E320 Wagon, 2005 C230K SS, 2010 Accord LX w Eibach & Koni FSD's
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2,879 Posts
What are your #s? How many miles on the engine. 103 engines are just plain dirty and are difficult to smog. New plugs (non resistors), air filter, and oil change are a MUST! Also, clean or replace cap & rotor. How are your valve seals? Make sure engine and cat are HOT and do not turn off the engine when you take the car in.

Mine just squeaked by again and I'm good for two more years. Might be sending her to Pick and Pull next time :crybaby2:
 

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2009 ML320 & 1984 190D
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229 Posts
Discussion Starter #3 (Edited)
Thanks for the fast reply!
91k miles on Odo.
Ok, first smog was a mistake on my part... car was running super I thought it would fly thru...
It didnt...



So... I got it all dialed in for 2nd test.
New correct plugs with maybe 50 miles on them.
Old ones were not correct, but looked clean, but no idea on history but no sign of burned oil on old plugs.
Cap and rotor are new. Plug wires look and test out fine.
All new fluids, and filters.... and I mean all!
Yes to it being hot when I drove it into the test center....
They did a "Pre-Test...


Judging by the engine internals, its been well serviced...

 

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2009 ML320 & 1984 190D
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229 Posts
Discussion Starter #4
Did some tuning and adjusted the EHA a little.
Engine seems a little snappier off Idle.

Next I did some reference readings using the Duty cycle and a O2 tester I have...

Here is a video of the two at idle with the duty cycle set about 50%..
Click on pic to watch.



And then at about 2500rpm...



I also tried and recorded the two meters at 70% and 30% at idle and 2500rpm...

The O2 seems to be working but seems sluggish at idle... not sure if that is correct, but I have a new O2 ready to go in at soon as its cool..

I would value anyones input!
 

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86 300e Anke
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1,252 Posts
Well, when was the last time you changed the fuel filter?
As I understand it, High HC happens under LEAN conditions...

You may want to check your fuel pressure and do the filter...
Of course, if I have it backward, then ignore me. :p
 

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2009 ML320 & 1984 190D
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229 Posts
Discussion Starter #6
Thanks for the input..

All filters are new.

Fuel pump output and pressures are bang on.
Upper chamber pressure was 5.45 Bar and Lower was 5.05 Bar, which I believe is correct.

So I just changed the O2 sensor....
HUGE difference in the speed of the tester's LEDs!

At Idle...


At 2000rpm..
 

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1992 300ce, 3.0, 207,00 mi.
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335 Posts
How come the max allowed values are different on both test? Anyways I wish the max allowed HC's was the same allowed for mt 90" CE, for my car the max allowed is in the 60-70ppm range, barely made it last two tests. High HC's=unburnt fuel. Last retest leaned out fuel mixture (inc duty cycle to around 65%) and put in tank of reg (87) fuel (burns faster). Got me through the last test but I'm sure I'm due for a new cat, main purpose is to reduce HC's out the tailpipe. Good luck.
 

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2009 ML320 & 1984 190D
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229 Posts
Discussion Starter #8
First one was the full on test, and second was a "Pretest". they said it would tell me if it might pass.
 

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89 300E; 00 E320
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2,515 Posts
Here is the site to check your static readings and they look to be in order to me: BOSCH KE3-JETRONIC MIXTURE ADJUSTMENT

Looks like your using the black probe in #2/ground of X11. Not that it really matters as long as you know which way to adjust: ccw is lean and clockwise will richen mixture. But that is why the static readings are 89.9 instead of 10; if you want the static reading to match landiss then put red probe in #2.



As it is now with black in #2 your showing 46-53 and if you richen the mixture a bit then you will see something like 51-59.
 

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86 300e Anke
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1,252 Posts
Thanks for putting that up again! THIS TIME Ive saved it off to the HD, so I dont have to go searching for it EVER AGAIN!! :p
:thumbsup:
 

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2009 ML320 & 1984 190D
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229 Posts
Discussion Starter #11
Looks like your using the black probe in #2/ground of X11. Not that it really matters as long as you know which way to adjust: ccw is lean and clockwise will richen mixture. But that is why the static readings are 89.9 instead of 10; if you want the static reading to match landiss then put red probe in#2
I am confused...
I have 69.9%(70%) reading with Key on engine off...
That is correct I thought...
 

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89 300E; 00 E320
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2,515 Posts
You said that at full throttle you got 79.9. Landis website says 20.

You also said that at a bit of throttle you got 89.9. Landis website says 10.

So do you have a picture or a video of which color probe is in #2/ground of X11? I guess you could just say which one too.
 

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2009 ML320 & 1984 190D
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229 Posts
Discussion Starter #13
Will take some pics later...
At the moment I have the Black or signal wire from the DMM in #2 or ground socket...
 

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89 300E; 00 E320
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2,515 Posts
Yes, seems like conflicting information doesn't it. Do you have the California controller with push button and led.

If so follow the directions on the landis website to enter correct mode.

The good news is that it sounds like you may have already fixed the primary issue with the new lambda sensor and you said it was responsive just off idle; and the reading you are getting in the videos seem good. Maybe there is no problem anymore.
 

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2009 ML320 & 1984 190D
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229 Posts
Discussion Starter #15
Confused...
I am sure its a CA car.
16 pin diagnosic panel near battery with LED.
Pressing it once for 2 sec gives me one flash..
Pushing the button again for a few secs makes no difference to the readout.

With my DMM set up like this:
Black probe in #2
Red wire in #3

Ignition on engine off I get 69.9%.

Deflecting throttle gives me 89.9%.

Reversing the pins on the DMM gives me 30%.
Deflecting the throttle gives me 10%...

I read in the FSM that a reading of 30% means engine temp sensor issue...

HELP!
 

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1999 E320, 2000 E320, 2003 E320 Wagon, 2005 C230K SS, 2010 Accord LX w Eibach & Koni FSD's
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Last retest leaned out fuel mixture (inc duty cycle to around 65%) and put in tank of reg (87) fuel (burns faster).

The tech who smogged my vehicle filled my tank with regular gas. I thought he put gas in my car beause it was low on fuel. When I saw the receipt for regular gas, I was pissed because my baby likes steaks and not hot dogs! Now I know why. Don't know how much this help, my car passed smog and thats all that matters.
 

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2009 ML320 & 1984 190D
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229 Posts
Discussion Starter #17 (Edited)
Update

I am confused by the STATIC KOEO readings I am getting from the X11 connector on the LH fender.
I will be referencing the "Duty Cycle" Holy Grail at the Landis site here somewhat..
BOSCH KE3-JETRONIC MIXTURE ADJUSTMENT


I will try to explain what I see and reading with pictures as I am really confused whether there is an issue or its me!

Car is a CA and Fed smog complient for 1991 MY according to the underhood sticker with the 16 pin diagnostic port near the battery...



Pushing the button on the Diagnostic for 3 seconds or so gives one flash from the LED... No codes.
Holding the button or doing anything else does nothing... I read on Landis site that holding the button in for longer puts the LED in solid and allows the X11 connector to output duty cycle... it does on my son's CA 1988 300TE, but not with this car.

So, KOEO, I plug in my Craftsman DMM...
I heard that the Craftsman DMM's can read backwards, but for a start..
Red into #3 and Black into #2...
I get a 69.9% reading...



Reversing the leads to the DMM so Black is in #3 and Red in #2, I get 30%..
I am gonna leave it like this for the following tests for clarity...



Now I read on Landis that deflecting the Air Flow Sensor Plate should reduce the reading to 10%...
I get no change..


However..
Moving the throttle linkage a small amout does reduce the reading to 10%.



And cranking the throttle to WOT gives me a 20% reading..



Starting the engine from cold it changes the static reading to 50% while its in Open Loop.



Once the engine drops into closed loop after a few minutes, the reading begins to cycle, and I have it set about 50%... so it varies between 45%/55% at idle and about the same at 2500rpm... so thats good!

so a quick recap..
Now aside from the 30% at KOEO, and no change when the air sensor plate is deflected, the 10% and 20% are correct...

Now it gets confusing....
After the engine was warmed and in closed loop...
I did not touch the ignition key, but stalled the engine by deflecting the Air Sensor Plate... the engine stopped, and I was back in KOEO... but now I am reading 70%!


I deflected the Plate more... and I hear a click from the battery area which I assume is the MASS, and the reading drops to !0%!



Now I move the throttle linkage... and I get no change from 70% at either throttle opening.

I go and turn off the ignition and turn it back on again...
Now its changed again...
KOEO I get 50%...



Deflecting the Air Plate I get 40%..



Moving the Throttle off idle I get 10%..



And WOT I get 20% again...
 

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Discussion Starter #20
Correct.
I have about that with filter on of off and between idle and 2500rpm its within spec
 
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