|
PA Emissions -Failed
Failed Hydro Carbons big(?) and CO please help gurus.
Mode-----------CO%---------------HCppm-----------------RPM-------Dilution 2speed idle---Limit-Reading-P/F-----Limit-Reading-P/F---Read-Resu-Read-Resu Idle----------1.2---8.74----Fail-----220--577----Fail----703-Valid--18.1-Valid 2500 rmp----1.2---8.34-----Fail-----220--336----Fail-----2548-Valid--18.0-Valid I am thinking O2 sensor. Any Ideas where I should start? Edit: this would be on my 86' M103 300E -as per my sig. BTW |
Also- have had increased gas consumption from 17-20 mpg down to 13-16 mpg.
-Anyone? :confused: |
I think O2 sensor is a good guess. My 86 Supra, which is L-jetronic based, had the same exact symptoms (except for my mileage was still OK as far as I know). I checked, changed and adjusted EVERYTHING to no avail, until finally my friendly local mechanic said "It is the O2 sensor" (he diagnosed it over the phone for no charge - can't complain about that). Anyway, $35.00 later I had perfect (near zero) emissions scores. So if the O2 sensor is not too expensive, I would try it. On the other hand I have no specific knowledge of your car so maybe someone else has a more likely answer.
|
Test the O2 sensor. Do a search - many discussions of the subject.
Duke |
Quote:
I went out and picked up a 1990 mustang 302 o2 sensor as per this article: http://business.baylor.edu/Richard_Easley/autofaqs/o2sensor.htm for $41.00 after tax, I will spilce it up tonight and install it tomorrow. This seems to be a likley candidate for all my symptoms from what I have read. Hopefully it cures me. I also noticed in my reading here that ideal conditions for an older cat like mine are well heated up and run hard right up to the actual test, which I did not do. (The plugs & wires are from this last summer and I always use 93 octane by mfg recomendation.) So I will do this and keep my fingers crossed. Anyone out there know if there is a way to test an o2 sensor, out of the car? And or in the car an running? |
Quote:
Will try again. Thanks |
You are almost off the chart on both HC and CO - I think you have something more basic than the O2 sensor wrong, like the fuel distributor, EHA, start valve, or the warm-up system. Something would appear to be dumping a lot of unneeded fuel into the cylinders, which is consistent with your note about fuel economy. If you don't deal with this promptly, you will foul your converter.
|
Quote:
As I am off to that now I will moniter this thread for any sugestions. Multi-Meter is fired up and ready. Just got to figure out where to stick it. |
Have you done just a exhaust sniff test?
I did that a few months ago and my eyes were teary with richness. Not horrible, but not right. I checked the easiest first- The temp sensor which read about 4.8k ohms. I R&R it today and remeasured at 70 F, 5.6k ohms. Seems much better- last time through emission testing it was only NOX that was very close. I'm hoping it was out of range last year... New plugs and an oil change before we pay the test station. Michael |
rookie hits the driveway
did 3 tests
1) at X11 (ignition on engine off) pin 3 red banana to V/F/C/Ώ/mA/uA pin 2 black banana to COM Dial set to % duty reading 30.1 2) at X11 (engine running) pin 3 red banana to V/F/C/Ώ/mA/uA pin 2 black banana to COM Dial set to % duty reading 50.6 3) in passenger footwell black wire lead from O² Sensor to red banana to V/F/C/Ώ/mA/uA aligator clip to front right fender inside engine compartment to black banana to COM Dial set to % duty reading 0.0 Am I doing this wrong? |
Quote:
Also search posts under my user name. I've made many, many posts on emission test issues. Duke |
Quote:
I had a center muffler failier around Halloween, when I replaced It (both it and rear muffler had been off for 1½ months) I expected to see a big improvement in mpg that never appeared. It has been a little slugish as well. Was that temp sensor on your 86'? If so where is it exactly (side of the block?) and any tips on the test? |
Quote:
http://www.peachparts.com/shopforum/tech-help/88269-87-300e-power-loss.html?highlight=EHA+testing http://www.peachparts.com/shopforum/tech-help/108163-oxygen-sensor-voltage-question.html?highlight=oxygen+sensor+test http://www.landiss.com/mixture.htm and more like em. what do you think of my test results? I would have rather seen a low reading than no reading as I am new to this and think I am maybe doing something wrong. |
Out of curiosity, have you noticed a drop in the full throttle power to go along with the drop in fuel economy? If so, your cat could be at fault (partially plugged).
I once had a Honda that melted it's cat, giving me a lack of highway power and 15mpg. 2 dealers gave me idiotic diagnoses of 1) failed ignitor in the distributor and 2) plugged fuel filter. It finally got so bad that I was sick of dealers doubting my plugged exhaust theory that I pulled out one of my ice axes for the next service manager and bashed some holes in my muffler. The car remained silent and the service manager believed me. What was remarkable though was just how far the fuel mileage dropped before the lack of power was felt. If you're playing underneath with the O2 sensor anyway, it couldn't hurt to take a peek at the cat internals. |
Quote:
Of course I am hopping the cat is not dead. If it is I will try to achieve a $150.00 spent on emissions waiver before going that route. Having just replaced everything behind the cat already I suppose its time may have come. What should I look for if I can see in there? |
I'm going to have to hope an experienced tech will answer this one for you, as I have never seen the inside of an MB cat, although at the point where you see a drop in fuel economy and performance, any damage to the cat internally, if it is to blame, should be obvious.
|
Quote:
Your high CO readings indicate a rich mixture, so the Lamda system is probabably not functioning properly. A common culprit is a faulty O2 sensor. The Lamda engine temperature sensor could also be fauly - sending a false low temperature signal, so the system always thinks the engine is cold, or it could be the EHA or control unit problems. Duke |
Quote:
I got a reading (by puncturing sensor side of black wire to ground) of 0.451V at start up (coolant temp 80°C) slowly (over 20-25min) descending to 0.349V. Increase of rpm to 2500 would raise reading to about 0.360V at bottom end of the reading. That and this... Quote:
|
Coolant temp sensor reads 475Ώ at 95°C (aprox.) out by more than 100.
Normal range is 290-370 Ώ at 80°C should be around 220 at 95°C Is this a typical sort of failure? Edit: retest - am getting 720-750 Ώ at 80°C (reversing-polarity for cross testing) and dropping but, is not in correct range Can I jumper this to 0 resistance to see if it runs good or is that not ok for computer? |
What do you mean by "reversing polarity for cross testing" Are you saying that when you reverse the probes you get a different resistance reading? The thermistor should read the same regardless of which probe is on which connection.
If you believe that the sensor is bad then you could hook up a resistor of what ever value it is supposed to be at running temp and if the engine is at running temp then it should be happy. I don't think zero ohms would be a good idea. |
Quote:
Quote:
Thanks for your response. Marty |
Unplug the O2 sensor and look at its open circuit voltage. It should be over 450mV. Engine and exhaust must be fully warmed up. Also check for continuity of the O2 heater.
I have the following temp sensor values for '84 M102. I'm not sure if they apply to later KE systems, but I think they do. 20C 2.2-2.8 Kohm 80C 290-370 ohm 100C 140-220 ohm. Take readings at two temps - 20 and 80 are probably easiest. Duke |
am pretty sure it is rich.
I had a center muffler failier around Halloween, when I replaced It (both it and rear muffler had been off for 1½ months) I expected to see a big improvement in mpg that never appeared. It has been a little slugish as well. Was that temp sensor on your 86'? If so where is it exactly (side of the block?) and any tips on the test? I think all the temp sensors are suppose to be 2.6-2.8 k ohm. Sounds like you could really use a factory manual=) AKA looks like my dash gauge might also be shy by about 5 C. At 100C, the sensor read about 800-900 ohms. I was thinking the range should be 500-600 ohms-but don't know without checking a bosch book. I'm headed for emission testing soon too. My plan of attack is new plugs, oil change, and O2 sensor. It did not start today instantly at 75 F, so I'm guessing my mixture is off a bit. Michael |
Quote:
I found the water temp sensor Ohm's range at the temp chart in the /Engine Manual-Combustion Manual-07.3 Mechanical/electronic gasoline injection system (KE injection)-121 Testing electrical components of KE injection system. page 60 Temperature °C........Resistance kΩ -20........................15.7 -10.........................9.2 0............................5.9 10...........................3.7 20...........................2.5 30...........................1.7 40...........................1.18 50...........................0.84 60...........................0.60 70...........................0.435 80...........................0.325 90...........................0.247 Same resistance values apply to KE intake air temp sensor. I think this chart applies to these 2 sensors for all KE systems but don't know for sure. My water temp sensor is not in line with these values. I may also have a bad o2 sensor (wish I had a scope to get a clear view) Now I am waiting for my water temp sensor to arrive. 75°F ay...must be nice. Marty P.S. anyone know if there is a better tool than a 22mm crows foot to get these sensors off and on again? |
Quote:
I will post my results when I have them. Marty |
Good luck....
Been there last Saturday. Unless you've got a fancy Stallwillie or they revised the lift bracket.... revise your game plan. You'll need to take the 2 6mm allen bolts out and rotate the bracket out of the way. The bracket has the water oulet for the head.. so if you do it carefully- it won't leak. If not, drain the coolant and replace the o-ring seal while you are at it. Looking at mine- the coolant gauge sensor is out of range by a similar amount. The fan switch- I cannot remember it comming on even parking the car in 100F weather. So, I'm guessing that isn't right and it needs replacing too. There are seals underneath the sensors... Makes me wonder about the sensor on the intake too... Michael |
Quote:
Quote:
Quote:
Thanks for your input Michael I should be able to put my water temp sensor in in the morning in this snow we are having, and I'll post my results. Marty |
Try www.stahlwille.com. Exchange rate sucks these days... but their wrenchs, sockets and definately the allen & torx sockets are better than snap-ons. Infact, I've thought about liquidating some of my mac and snap-on stuff on ebay and trading up to stahlwille.
The only on I see might be one of the MB a/c crowsfeet. 440-22? Not that hard to do... I'll let you know about the temp switch in a week or so. Michael |
http://www.samstagsales.com/mercedes/mb000589710300.jpg
I'm guessing this would work or you could make something similar. Kinda rich for my blood though... could use it on A/C and torquing those front struts=) Michael |
Well its been a while but I have finally got her running and am ready to have emissions retested. The first appointment I could get is for Tuesday at 10AM
So far I have: Changed the water temp sensor. New cap & rotor. Oil change. 2 big bottles of Techron in a tank of 93 octane. Being a nervous type I was looking at my duty cycle at X11 (engine fully warmed). It starts out at about 45% and fluctuates but it heads down to the just under 10% range and fluctuates around there (8-12%). Is this ok? I was thinking that it should fluctuate closer to 50% but don't really know. I just want to do whatever I can in the next bit of time before the test to improve my chances. I have read Duke's instructions for fully warming up these cars and keeping them at high idle right up to the test. But is this duty cycle reading an indication that there is still a problem with the lambda system? |
I don't like the sound of your duty cycle readings. Fluctuation is normal. In fact, if it doesn't fluxuate there's a problem. MB service data says the average duty cycle at idle should be within 10 percent of the duty cycle at 2000 revs, no load, so if you eyeballed an approximate 45 percent at idle is should average no more than about 55 percent at 2000.
Other's have reported results similar to yours, but it's never been clear to me what causes the duty cycle to drop and stay near 10 percent. There is either a problem with the system or with your measurement technique. On my '88 CA car I have to manipulate the button on the X92 connector to place the system into "test mode" to measure the duty cycle, but I don't think that applies to your car. Duke |
It is not what I had expected to see.
The reading was taken at idle with the car warmed up. If I disconnect the oxygen sensor it goes to a steady 50.x%, as it should, with no fluctuation. The car seems to be running very well so I think I will take it to the inspection on Tuesday and see how it reads. I will report back then with the results. |
FAILED again (only slightly better)
After:
New water temp sensor. New Cap & Rotor. Oil change. Techron still in tank during test. Fully warmed up...(run at close to 4000 rpms for about half an hour in advance of test) Mode-----------CO%---------------HCppm-----------------RPM-------Dilution 2speed idle---Limit-Reading-P/F-----Limit-Reading-P/F---Read-Resu-Read-Resu Idle----------1.2---7.25----Fail-----220--468----Fail----684-Valid--17.8-Valid 2500 rmp----1.2---6.27-----Fail-----220--254----Fail-----2531-Valid--17.4-Valid Some additional facts: I have yet to put in the new O2 sensor... In the course of my investigation I discovered a leaking EHA I suppose the cat could be called into question as well. The low duty cycle seems to point to a problem... One strange thing, when I test duty cycle Ignition on engine off I should get a reading of 70%-49 states car, but I get a reading of 30%? Duty cycle engine on starts at approx. 45% then descends slowly down (over about 5 min) to the 8-12% range where it hovers (fluctuating) If I pull toe O2 sensor lead I get 50% but if I pull the water temp sensor I get 70% not 30%? Any advice/support appreciated. (we'll get her through this... the EHA alone will buy the waiver) |
Your CO reading indicates a very rich mixture. Likely there is something wrong with the lamda system, but it could be almost anything associated with the system.
Once you find and correct the problem with lamda, the CO should be no more than about 0.5% If more and HC is still high the catalyst may be called into question. Duke |
Emissions Tester
Hey I work as an emissions tester for my area. I will tell you this much, once a mercedes turns 10 years old, you better pray it passes. I see alot of Mercedes that are over 10 years old FAIL. I have a C Class mercedes which FAILED when it was only 8 years old, turned out my CAT. had unmounted from its proper postion, and that simple fixed passed me. The problem with Mercedes and Some Volvo's is they come with horrible CATs, and expensive to buy and replace. Also some mercedes models have questionable Air Mass Meters that were made by Bouch and this alone can simply mess your car's exhuast emissions to a point where you will not pass since your car's not operating properly. I personally think its your CAT, you will need to replace it inorder to pass. This is very common on mercedes, and I've had some people tell me its costs them an arm and a leg. So give your CAT and Air Mass Meter a check, and you'll have your car on the road again. Hope this helps.
p.s. One of the Volvo's that failed last week. The tech told me he knows their cat's suck, that's why we all drive chevy's at our dealership.... |
I would expect a better analysis from and emission test tech. Don't you have to go through some kind of training? As a former emissions research engineer, I can assure you that I had LOTS of training.
I fail to find a cause and effect relationship between catalyst mounting and catalyst effectiveness, unless you are taking about a leak, which would cause a noticeable noise. The CO indicates an A/F ratio of less than 12.5:1. The lamda system should keep the A/F near 14.7:1, which would yield CO below one percent even if the car had NO catalyst at all. An over rich A/F to this degree will prevent the three wasy catalyst from energizing any oxidation or reduction reactions. I suspect that a lot of properly performing catalysts get replaced due to this type of faulty analysis. Catalysts do degrade with time as I've pointed out in previous posts, so "conditioning" becomes important, which is an owner responsibility. http://www.peachparts.com/shopforum/tech-help/117048-successful-ca-asm-emission-test-ke-fuel-system.html#post833484 The owner needs to fix the lamda system first and only judge the catalyst performance when the lamda system is functioning properly. The car in question does not have a convential hot wire anemometer MAF sensor like a "modern" car, but its mechanical air flow momentum sensor should be checked for proper operation. Duke |
Quote:
I am beginning to suspect something directly related to the fuel metering ... the air flow sensor, EHA, or the distributor itself. The leaking EHA is immediately apparent. I am hoping its replacement gives me the duty cycle I am looking for. |
If you have not already done so, go to the following site and download the complete 103 engine manual. Also download all the fuel system info from the 124 CD. Study the information so you understand the system, then refer to the various tests and repair procedures.
http://mb.braingears.com/default.htm The KE fuel system is complicated, but logical, and once you have sufficient "system knowledge", you should be able to troubleshoot and isolate the exact problem. It makes a lot more sense to approach the problem this way rather than guessing and throwing parts at it hoping that you eventually solve the problem Duke |
Quote:
I guess I missed a very basic step when checking duty cycle. Red Banana (+) needs to be in the #2 terminal. Black Banana (-) needs to be in the #3 terminal. I had it reversed. I just assumed, incorrectly, that it was the other way around. So my readings were the opposite of correct; except for O2 sensor pulled (the opposite of 50% is 50%). Anyway my new readings make more sense: Ignition on engine off = fixed 70% duty cycle (or 69.8% fixed) Idling (fully warmed up) reading fluctuates and climbs to over 90% (trying to lean) Replaced seals in the EHA… still leaks. Replaced O2 sensor… and first I have to say again, “I am an idiot”. I had leaned it out a little, earlier, at the tower to see if the duty cycle would respond… it did not… So I replaced the O2 sensor and tried to measure duty cycle with the Red lead still plugged into the Amps socket! and got a steady 92%… very confusing. Once I figured out my mistake and fixed my meter I was still getting a high (lean duty cycle and thought I had not solved anything with the O2 sensor… very depressing. Trying to richen the mixture at the tower it felt like it was not turning the adjustment screw and I thought I was screwed… until I realized I had grabbed the 2.5mm Allen key instead of the 3mm… ¼ turn later I had a fluctuating duty cycle in the high 40’s% Thank you all, particularly Duke2.6 for hanging with me through this, for me, very educational process. I will post my emission results when I get the retest. Till then… |
$$$ limit
How much $$$ have you spent so far to get your car in compliance? I found a FAQ on the www.drivecleanpa.state.pa.us website that states you can get a one year waiver if you have spent $150 or more to bring your car into compliance:
What happens if a vehicle fails the emissions inspection? If a vehicle doesn’t pass the emissions inspection, you must make emissions-related repairs. After these repairs are made, the vehicle can be re-inspected for free, within 30 calendar days, at the station that initially conducted the inspection. If you wait longer than 30 days, or take the vehicle to a different emissions inspection station, the reinspection is not free. In addition, if the vehicle still doesn’t pass the inspection, in most cases you can get a one-year waiver if you have spent a minimum of $150 on emissions-related repairs. In some cases, you may be required to spend more if the needed repair is the only repair that will address the problem. Check. |
Quote:
I am up to about $160.00 so far (Cap & Rotor, Mustang O2 sensor, and water temp sensor) I missed my first free re-inspection when the fan clutch bearing bracket failed and the job (mostly finding the right used part) took me 33 days. The engine has never been cleaner as taking off all that stuff gave me the opportunity to scrub off a lot of gunk. Based on my duty cycle though... I think I might have her in spec. I think my gas savings over the year might cover the cost of the repairs... and I have a Toyota PU from my work that will get me around till I can get her on the road. Sure do miss the Benz though... but knowing she is running great will make our reunion all the better. Thanks for your thoughts. |
Passed
Mode-----------CO%---------------HCppm-----------------RPM-------Dilution
2speed idle---Limit-Reading-P/F-----Limit-Reading-P/F---Read-Resu-Read-Resu Idle----------1.2---0.26-----Pass-----220--191----Pass----703-Valid--15.0-Valid 2500 rmp----1.2---0.29----Pass------220---49----Pass---2580-Valid--15.0-Valid Once again...Big thanks. |
Your effort was exemplary and proves that following a systematic troubleshooting procedure will eventually get you to a solution, and this is certainly better than replacing parts willy-nilly or buying a bottle of "smog test in a can" based on guess work, which seems to be pretty common, both among DIYers and professional shops.
Since the service information for these engines is available on-line and can be downloaded for free, there's no reason not to follow this approach and educate yourself on the system operation and use the published troubleshooting and diagnostic procedures. Of course this takes time. Some expect a silver bullet from the Board, but there aren't any to pass out. Your HC at idle is still high and would probably fail the CA two-speed no load test that is used in some areas of the state that don't have significant air quality problems. Before the loaded dyno test was phased in back in '99, we had the two-speed no load test. The 2500 RPM test was run first. Do they run the 2500 RPM test first in PA? This would help heat up the catalyst, but my car's idle HC count was always higher at idle and on the ragged edge of the limit a couple of times. There was probably still enough O2 in your car's exhaust to enable more oxidation if the catalyst was hotter, which is why "conditioning" is important, especially as the catalyst slowly degrades with operating time accumulation. One way top keep the cat hotter is to understand the effect of ignition timing on both EGT and peak flame front temperature, which is the source of NOx. http://www.peachparts.com/shopforum/showthread.php?p=833484#post833484 Duke |
Quote:
Unfortunately due to scheduling constraints this time, I left it for them. I imagine it had been sitting for at least a half an hour... after listening to the engine, looking at the duty cycle, and sniffing the exhaust I was confident enough to leave it there for them to do their worst. Besides which I had already exceeded the $150.00 emissions repairs amount to buy a waiver if it had failed. It passed the first time through. If you fail the first test here in PA they do a "preconditioning" (top off the oil if necessary, and rev it at 3000 for 3 minutes before doing a retest. If you fail the retest with "preconditioning" you have 30 days to get a repeat of the whole procedure at no additional cost. |
Hey there,
Thought I would chime in in regards to your catalytic converter since I went through a similar situation with my non MB vehicle. If you are running rich to the point that your mpg's and power have dropped considerably there is a strong likelyhood that you have cooked your catalytic converter. |
Quote:
Duke |
One year later. (4/29/06)
Passed again...
Mode-----------CO%---------------HCppm-----------------RPM-------Dilution 2speed idle---Limit-Reading-P/F-----Limit-Reading-P/F---Read-Resu-Read-Resu Idle-------------1.2---0.66----Pass-----220--189----Pass----727-Valid--14.9-Valid 2500 rmp------1.2---0.56----Pass------220---80----Pass---2329-Valid--15.0-Valid Not so sure of the exact test conditions, as I was not present at the test station during the test, but the tech said he let it idle in advance of the test as I had requested. Less than two month old plugs and O2 sensor. Regular Sea-Foam treatments (1/3 bottle ported into the intake manifold and burned off at 2500 rpm's) An interesting side note: my gas cap failed the first pressure test and the tech called me to advise... he gave me the option of supplying my own part... I had purchased a new gas cap seal from Phill a little while back so I told him I would bring it down. My gas cap had been run over by something in a little memory related filling station accidet I had over the winter so I was not completely confident in it's integrety, so I stoped at the local parts chain and bought a $3.97 replacement cap on my way to the test station as a backup. When I got there I handed the tech the new cap fresh from it's packageing. The NEW cap failed the pressure test! So I popped the old seal off the OEM cap and replaced it with the fresh one, while the tech stood shaking his head. The 20 year old run-over MB cap with brand new seal proceded to pass. Moral: Beware cheap junk! |
Thanks for the follow-up.
Does your car have to be tested every year in PA? In the future I suggest you find a place than can run the test while you wait. Be sure the car is properly "conditioned" by fully warming it up, and get it on the machine as soon as possible so the catalyst doesn't have time to cool down. Duke |
Man I am sure glad that the whole state does not do that. Although I do think they should, but in York County we get the visual inspection for all components for non-OBD II cars and a gas cap test. OBD-II cars get plugged in to the computer and it checks to see if everything is in working order. No tail pipe sniffer here. I guess it is only for the larger cities or counties in PA that get the real test.
Edit: Yeah here it is $45-$50 and basically a useless test every year when the car has it normal yearly inspection. |
Yes yearly, and only in a few countys for tailpipe testing. There have been, failed, efforts to make the whole inspection process biannual.
Unfortunatly the mechanics I have the best relationship with are not certified emmisions testers and outsource that job, making my test time subject to the whim of a busy shop that doesn't know me from Adam. If it becomes necessary at some point in future I am sure I will be able to make it happen though. |
| All times are GMT -4. The time now is 04:21 AM. |
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website