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300E Now Running Rich
Well, I went through an intermittent no idle situation. I ended up replacing the airflow position sensor and the idle has been fine ever since. That was about a month and about three tanks of fuel ago.
I filled up day before yesterday and fuel mileage was SERIOUSLY off. This morning I ran my fingers in the tailpipe right after shutting it off and it is solid black soot. I guess I'm headed for the manuals. In the meantime I will get out my other car. Bummer!
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2001 SLK 320 six speed manual 2014 Porsche Cayenne six speed manual Annoy a Liberal, Read the Constitution |
#2
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Have you checked the duty cycle at all?
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TC Current stable: - 2004 Mazda RALLYWANKEL - 2007 Saturn sky redline - 2004 Explorer...under surgery. Past: 135i, GTI, 300E, 300SD, 300SD, Stealth |
#3
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Quote:
Have you checked the duty cycle on the X11? Maybe its throwing a fault telling you that one of the sensors is had it? Maybe O2 sensor?
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Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out. Check here for compatibility, diagnostics, and availability! (4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!) 82 300SD 145k 89 420SEL 210k 89 560SEL 118k 90 300SE 262k RIP 5/25/2010 90 560SEL 154k 91 300D 2.5 Turbo. 241k 93 190E 3.0 235k 93 300E 195k |
#4
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How "off" is it? I agree with checking duty cycle first.
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Eugene 10 E63 AMG 93 300te 4matic 07 BMW X3 14 Ford F-150 Fx2 |
#5
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I just discovered the sooty tailpipe this morning before walking inside for work. I haven't had a chance to so much as get it home and raise the hood yet. I will check trouble codes at both places and go from there. I have a duty cycle meter and an LED code reader that I made.
It's hotter'n hell right now, and I plan on flying in the morning, so I'll park it and get to it in a few days. Thanks for the comments & suggestions. I'll probably be back for more in a few days. I might mess with it early Sunday morning before it gets hot. Very easily could be the O2 sensor sense it hasn't been touched since it left Germany 25 years ago.
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2001 SLK 320 six speed manual 2014 Porsche Cayenne six speed manual Annoy a Liberal, Read the Constitution |
#6
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Quote:
Also FWIW my O2 sensor didn't throw any codes when it crapped out (maybe not hitting the code threshold?). Lambda was off though.
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TC Current stable: - 2004 Mazda RALLYWANKEL - 2007 Saturn sky redline - 2004 Explorer...under surgery. Past: 135i, GTI, 300E, 300SD, 300SD, Stealth |
#7
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Duty cycle should be solid 70% with engine idling cold, open loop. Then it should start fluctuating at around 50% when the engine goes into closed loop.
As far as the O2 sensor, it's really cheap if you splice in a '90 Mustang GT O2 sensor Bosch part# 13953 (available at ANY parts store) for around $40, as opposed to the factory sensor @ $100. If that's not the problem, probe the EHA with your volt meter. Specifically pay attention to the voltage when you rev the engine above 3000rpm. The EHA can seriously affect mileage (like 15mpg bad) if it goes bad in a certain way.
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http://i193.photobucket.com/albums/z...-RESIZED-1.jpg 1991 300E - 212K and rising fast... |
#8
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Yeh I would bet O2 sensor Larry. Definitely start there. At your mileage it's well beyond time and even if it's not that, it's probably going from rich to lean very slowly and affecting your power and fuel economy to some extent.
It won't throw a code since all it checks for is voltage.
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2016 Monsoon Gray Audi Allroad - 21k 2008 Black Mercedes E350 4Matic Sport - 131k 2014 Jeep Wranger Unlimited Sahara - 62k 2003 Gray Mercedes ML350 - 122k |
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