nseibert

Hi,
just came back from my CAL Smog Test ordeal.
The vehicle failed with drums and trumpet tunes.

Got high HC and super high CO values otherwise it passed.

I bought the vehicle (95 E320 3.2L 6Cyl.) just about a month ago were it was already two month overdue.
The throttle actuator was totally shot, kaputt, discombubalated in the wiring.
Don't know the history, however believe the previous owner(s) tried to patch it just for sale.
They sprayed some red crud into the harness without doing any good. guess they said their prayers, but weren't heard.

The question:
1. the resonant idle flap moves restricted before complete assembly.
2. I can't tell if it operates as supposed to when all is bolted down.
3. Does this flap have an influence at above RPM's or can I dismiss this one?
4. Does the replacement e-gas computer perhaps have different data that can cause this rich running?

All in all I have only about two weeks to get it fixed because my temp permit will expire on the 15th of January 2014.
I'll inspect the spark plugs if I find a socket in my toolbox that fits, perhaps put new ones in.

I really need someone that might have the experience with this Model to tell me the answers to the above.

Please, NO MOTOR WIRING HARNESS REPLIES, I REFUSE TO BELIEVE THIS!

neanderthal

You should start with a basic tuneup.

Your numbers are really, really high, and most smog shops will tell you to replace the catalytic converter. $2800 for a remanufactured one at the dealer.

But it's rare for them to fail.

head over to benz world dot com (all one word of course) and ask your question there. You'll get more responses.

nseibert

Hi neaderthal,
first of all thanks for picking up on my post!
Yep, I had some feeling that there aren't as much responses here as it may be on bw.com

TNX

Plutoe

This is a double post the OP is not patient!!!

nseibert

It may seem so, but it actually is not!
So what, I got confused with similar looking forums and posted in a similar fashion.
However, this was posted after, I had new information.....
On the other hand "is it a bad thing?"

LEISTUNG1

IF THEY HAD A SMALL AIR FILTER IN THERE IT IS POSSIBLE THE DIRT CAUSED THE AIR MASS SENSOR TO FAIL AND NOT WORK PROPERLY THE OTHER THING COULD BE A BAD/SLOW O2 SENSOR IN THE EXHAUST BOTH OF THESE ARE DIRECTLY RELATED TO RICH RUNNING. THAT FLAP IN THE INTAKE HAS NOTHING TO DO WITH IDLE SPEED.

nseibert

Thanks for your reply LEISTUNG1, in regards to this very rich running vehicle..

I had cleaned the MAS and did a static test on it. Both numbers looked pretty good.
The Air Intake Filter must have been in there for some while, judged by its condition and the gap it provided to have air (dirty) pass right through.
Despite my cleaning effort, I also ordered a cheap one just in case. Cheap one seems to act the same as the old one, except that the ZERO airflow voltage is a little higher.
I believe the computer can compensate for small variations. Or there was just a breeze going through?
I measured the O2 Sensor voltage at idle and at ~2500RPM with an DVM (fairly precise). Then it crossed my mind to actually see the signal as it is and connected an Oscilloscope.
The darn thing is as happy as can be. I would post the image from my storage scope but used the slots for fuel injection timing signals.
The O2 toggles between approx. 800mV and something like 30mV.
The signal crosses about 5-6 times during 1 Second time period.
I am thinking to just throw it out and put a new one in and check it off.
But nope, it showed me the finger and I can't let that slide.

That problem turned out to be the e-gas computer that the PO decided to destroy by ignoring the CEL (Black tape taped over it) must have really bothered him.
I replaced the e-gas (ebay not new) and idle along with everything else is good now.
The Resonant Idle Flap is still going a little rough.

Just an CO of 4.65% or at least >3%
Talked to a Performance Muffler Shop they wouldn't even suggest to replace the CAT until the rich running is fixed.
I was told that if there is a new CAT installed it will still fail smog, since it can't knock down those high CO values and probably destroy the CAT in a short period of time.
I think they are right!

I did vacuum tests using a vacuum gauge the parts I tapped into look good.

Haven't replaced the Fuel Rail pressure regulator, since I can't see any fuel escaping.

If it would be common to have the Secondary Air Injection stuck in on, I'd say this could convince the computer to run richer.

Either there is something that adds oxygen to the exhaust, or the O2 Sensor's feedback is wrong, although it looks good on the scope.
Fuel injectors on this model run open loop (meaning there is nothing that checks the fuel amount/timing), except the feedback from the O2 Sensor and MAS.
Perhaps the Injector(s) are defective? The signals on the connector look fine!

Think, I gonna retire the problem for a few days, since I am starting to loose sleep over it.
Granted, one can throw all amounts of parts and money at it until it runs and passes (had this one wrong). But why replace something that isn't broken?

Thanks!

LEISTUNG1

NEXT IS THE CAT IN THE CAR THE FACTORY ONE OR DID SOME ONE AT SOME TIME CHANGE IT TO A CHEAP AFTERMARKET? CAN YOU CHECK YOUR FUEL PRESSURE? IF SO WHAT IS IT AND DISCONNECT PRESSURE REGULATOR AND REPORT WHAT IT CHANGES TO. WHEN THE REGULATORS GO BAD YOU MAY NOT SEE FUEL BUT THEY WILL HAVE A HARD HOT START ISSUE. IF YOU DON'T HAVE THAT IT IS PROBABLY OK. IF O2 IS OK THE ONLY OTHER THING IS POSSIBLY EGR IS NOT WORKING PROPERLY THE TUBES GET CLOGGED AT THE INTAKE LOOK FOR THE METAL PIPE THAT GOES INTO THE INTAKE MANIFOLD JUST BEHIND THE THROTTLE LINKAGE. IF THE FACTORY CAT IS INSTALLED I WOULD NOT REPLACE IT AS THE FACTORY CATS WORK REALLY WELL IF IT HAS AN AFTERMARKET CAT ALREADY INSTALLED THEN I WOULD CHANGE THE CAT THESE CARS LIKE RUNNING RICH AND THEY USE THE CAT TO KILL THE EMISSIONS. AFTERMARKET CATS ARE NOT CAPABLE OF DOING THE JOB.

nseibert

Hi again,
from your user name, it appears that there is some German heritage.

Anyway, the CAT is an aftermarket, from the looks, installed some time ago.
The car history is difficult, I know originally it was sold in Palm Springs. At approx.
100,000 Miles it was sold and then again, I believe somewhere 150,000-180,000 Miles
to the person I bought it from at 219,000 Miles.

Also, I don't know what the PO did take apart and possibly had some left over...

The EGR I had it taken out and poked with a piece of stiff wire into the pipe, without hitting any rough spots. Visually at the entry point I could see a very light layer of nicely Deer Brown deposit. This is what you would see on an exhaust pipe of a well adjusted 70-80's engine. There is not hte slightest hint of burned oil or other burned deposits.

The EGR does function via vacuum, hard to check while running since it is supposed to come on at higher RPM's controlled by the switch over valve.

At cold start I can hear the air pump, that I think switches off after the engine reaches about 50-60 C.

I don't have any warm / hot startup problems.

Before my temp expired, I experienced a tremendous loss in power after the engine reached operating temperature, with the A/C switched on. The Tempgauge was at 85-90C which is normal. I don't know what the Coolant Sensor to the computer is doing. I can't tell either if the power loss was due lean or rich fuel mixture. I would guess it was rich since I believe the fuel gauge was competing with the Tach.

The condition was:
Ambient Temp approx: 85F / ~28C
Air Cond was running.
Vehicle at Operating Temperature.

Once cooled off the engine had full power back.

I would like to check the fuel pressure, but my gauge has only adaptor for the SAE threads. Aside, the port requires a special one (Tire Valve Like) to open the valve.

Basically there is only one more thing left, however I checked on it too on several different places. The Harness seems to be fine with regard to the insulation.
I believe this one was made two years before the 94 Model came out, although I don't know when they started to install the ECO stuff, I might be lucky and have one that is not ECO.
The Throttle body came from Ebay and is stamped with 2004 so it is certainly the upgraded wiring. I can confirm this too, since I looked at it.

I haven't read the codes recently since I can't legally operate on public roads any-more. There was always the 6 in the built in test port, believe PIN 3 on a 16 port.
Right now, there is no CEL emitting, codes I have to check. The CEL went off on it's own I didn't clear it because I wanted to do more testing and see when it would go off on it's own. Bad part is, I didn't do anything but it went off on it's own?

nseibert

This is getting ridiculous, just went to read the codes Key ON engine OFF.
Guess everything is A OK, but it would probably fail the smog.
It is even more difficult without an exhaust gas Analyzer, big bucks....

I really do appreciate your input (LEISTUNG1)!!

Intermittent problems, like codes present and then NO codes at all, really point into the direction of a faulty Harness.
We'll know more once I let it idle to operating temperature.
There should be a code surfacing again.

When you are directly involved with things like that, it get's quite frustrating at times.

LEISTUNG1

UNDERSTOOD I HAVE WORKED ON MANY OF THESE THINGS OVER THE YEARS AND STILL DO I HAVE 2 95 E320 MY SELF BUT SMOG HAS ALWAYS PASSED. I HAVE FACTORY CATS AND I KNOW AFTERMARKET CATS DONT LAST A NEW CAT MAY MAKE IT PASS FOR NOW BUT IN 2 YEARS IT WONT PASS AGAIN. I AM ORANGE COUNTY IF YOU COULD MAKE IT HERE I COULD MAYBE HELP YOU OUT WITH THIS. GOOD LUCK

nseibert

Thanks for your offer!
Since my Operating Permit is expired, I would rather not take a trip into Orange.
I bet, two miles from home a Cop would cite me.

Cheers,
Norbert

nseibert

Here are images from the O2 sensor at idle and 2500RPM

fall_back2idle.jpg
E320_2500rpm.jpg

They look reasonable to me, although they are pretty round at the top.
This could mean a slow change / response?

Also, checked the secondary air pump e-clutch. It is working, but think it needs to be replaced sooner or later, she is noisy, but still pumping.
That is why the car sounds like a Diesel when cold, I believe.