Questions tagged [lean]
A condition where the air fuel ratio is not optimal and the engine is not receiving enough fuel from the fuel system
21
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11 views
Steady, low voltage on pre-cat O2 sensor while idling, but voltage increases upon revving
To test my pre-cat O2 sensor, I unplugged its connector from the ECU and stuck a voltmeter’s probes into said connector.
When I let my engine idle, my voltmeter shows a steady low voltage, oscillating ...
0
votes
1answer
62 views
What do you think of these spark plugs?
Still trying to diagnose an erratic positive fuel trims. Next step will be making sure that the lean condition i have is caused by less fuel delivered or weak spark not a vacuum leak. I pulled spark ...
0
votes
1answer
41 views
How can I diagnose if my engine is running lean or rich?
car is running poorly and wondering if it might have something to do with a lean or rich engine.
How can I diagnose this so that I know I am in the right direction and it is not one or the other?
I’m ...
1
vote
1answer
47 views
Motorcycle V-Twin CV carbs riding poorly on 1/4-3/4 throttle after carb rebuild
Background:
The bike Suzuki Intruder VS1400 model 2000, ran fantastic, but started to stall on idle when I used old fuel in it.
What I did:
I cleaned the two CV carbs. Didn't replace anything.
I found ...
1
vote
1answer
69 views
Spark Plug Deposits
So, I pulled the spark plugs today to check to see how the engine is running. After pulling all 6 spark plugs, I've noticed there is a white deposit caked onto the spark plugs. I doubt this is normal ...
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0answers
38 views
Engine feels like it will stall after Air/Fuel ratio sensor changed?
Got an 04 Acura TSX that's been baffling me for the couple of weeks. Accidentally bought an Upstream Oxygen sensor instead of the downstream so I thought might as well replace it since I have it (keep ...
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0answers
501 views
When second gear is engaged the car doesnt accelerate and engine doesnt rev up? audi a3 1.6 2005
I recently had a gearbox which went through the casing and needed to be refurbished. Had a new clutch replaced along with it. Once i picked the car up i began noticing that when the car goes into 2nd ...
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0answers
620 views
High LTFT (Long Term Fuel Trim) Reading
If someone can help me solving a lean condition issue, I'd appreciated!
I bought a 2002 Ford Focus ZTW (Zetec, at 100k miles) a month ago, and I noticed OBD2 always reads LTFT for both bank 1 and 2 ...
5
votes
2answers
122 views
Engine lean issues
Vehicle is a 2006 Ford Courier, started having hesitation/loss of power after fill up at a gas station that I'd never been to before.
I depend on it for transport so I'm forced to still drive it, ...
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vote
0answers
228 views
Help me diagnose my lack of power & lean condition
I have a 2000 Mercedes CLK 320 with the M112 V6 engine at 125 000 kms. The car has rough unsteady idle and is lacking a lot of its power - to illustrate, 0-100 km/h takes exactly 10 seconds, while ...
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votes
2answers
6k views
Help on diagnosing positive Long term fuel trim
My vehicle (Ford Fiesta 2014 Petrol) always have a positive long term fuel trim, which means its running lean mostly.
The log data that I recorded using torque pro can be downloaded here :
Torque Pro ...
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0answers
460 views
2 Stroke 70CC Scooter Engine
I own a scooter which I blew the engine in Dec 2016. I since replaced the defective parts in it and it now runs great aside of one thing:
Bottom end of the throttle is slugish (I'll elaborate)
It ...
5
votes
2answers
102 views
Is there a chemical limitation to the mixture an engine can maintain?
I know that the question/title is a bit ambiguous, but I couldn't wrap it in a single sentence, so please let me elaborate. You can change the mixture of an engine for whatever reason. Because of ...
2
votes
0answers
114 views
Emissions per mile of high MPG lean-burn gas-powered cars versus standard gas-powered cars
I am wondering if there have been studies or calculations of the NOx emissions per mile of high MPG lean-burn gas-powered cars versus standard gas-powered cars.
Honda made some great lean-burn cars ...
7
votes
1answer
3k views
Fuel Trim Readings
I have a 2002 Toyota Corolla (1ZZ-FE engine) and I am trying to understand the fuel trim values I am getting in real driving conditions from my scan tool. I have P0171 code (lean condition) that comes ...
5
votes
1answer
121 views
How much leaner can you responsibly run an old engine?
I've got a '76 Triumph TR7 and I was wondering this after I got its carbs tuned after its restoration. As many of you may know, old engines are initially not capable of running as lean as modern ...
5
votes
2answers
2k views
Can a permanently stoich or lean running engine ruin a catalytic converter?
It's known a cat can be burned by an engine running too rich for too long, but i wonder what the effects are of constantly running lean. Will the cat just be uneffective because of the lack of CO, or ...
12
votes
3answers
63k views
What's the meaning of a “lean” vs “rich” air fuel mixture
I'm learning about vacuum leaks on engine intakes and I'm hearing this terminology of lean air fuel mixture. I thought I heard of a rich mixture before too. What's a normal mixture referred to as? A ...
6
votes
1answer
205 views
2009 Aprilia RSV1000 - Piggy Back ECU, Should I get one?
I have an Aprilia Tuono, 2009. It seems to run lean after putting an Akrapovic exhaust on it. It makes exhaust popping sounds on deceleration. My boyfriend said I need a power commander on it to ...
9
votes
2answers
7k views
Strange surging and like it's going to stall, hesitant whilst idling
I have been having an issue with my Peugeot 207 (2008 model) 1.6L VTI petrol engine.
The cam cover was replaced by the garage but hasn't fixed the problem. I have lost faith in them. I have managed ...
24
votes
4answers
426k views
Symptoms of Lean or Rich carb settings on a motorcycle
I have a 1981 Yamaha XS650. I recently put in K&N stock replacement filter (ie, they are in the airbox and conform to the size of the original), however they may be leading to a leaner mixture ...
