Torque Pro MAF and other values at idle - Toyota Yaris Forums

grvdggr · 07-13-2017, 06:22 AM

Hello.
I have lost some acceleration and my car is consuming about 0.1 l/100 km more than before.

I post my Tourque Pro values in hope that I can compare my values to someone with a well functioning Yaris.
I have a 3 door 2000 model with the 1.0 engine.

Coolant: 85C
Idle revs: 600 rpm
MAF: 1,3 g/s
STFT: Alternating between 0-3,1% (Short Term Fuel Trim)
LTFT: -14,8% (Long Term Fuel Trim)
O2x1: Jumping between 0-0,8 V
O2x2: 0 V
Vacuum: 22,9 in/Hg

I have cleaned the MAF thouroghly a week before the test.

If you can't compare, is there anything about these numbers that doesn't seem normal?
Thanks.

tmontague · 07-13-2017, 07:10 AM

Your left's show a potential vacuum leak, I'd check that first

bronsin · 07-15-2017, 07:03 AM

Air filter change interval is more like 50,000 km. Under normal operating conditions.

Motzking1 · 07-16-2017, 04:14 PM

Your long term fuel trim number of -14.8 is way, way off. Far enough in the USA that it would trigger a check engine light. It's posible to be an air filter but it would have to be the most plugged air filter I have ever seen in my life! I live in Seattle WA so the air is crystal clear (because it rains, and rains, and rains and rains) I have 100k miles on my air filter and it flows fine. Do you live in a dusty or dirty environment?

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grvdggr · 07-16-2017, 05:20 PM

I drove my Yaris about 300+ km today and the air filter didn't solve the issue as I first thought. =(
Still slow acceleration, loses speed in some uphills.
My Long Term Fuel Trim has bad values, what could be causing the issue?
I've read about the EGR Valve, does a petrol 2000 Yaris have one?

Motzking1 · 07-16-2017, 05:40 PM

In the USA pretty much every car since 1978 have them. I assume your does. Let's think about this. The computer thinks it needs to put less fuel into the engine than would otherwise be needed for normal operation. There are 3 reasons why this could be. #1 fuel is entering the air/fuel mixture from somewhere it should not be. (Example leaking fuel injector, leaking fuel pressure regulator)[this is not common] #2 there is less air entering the engine therefore requiring the engine to require less fuel.(example a restricted air filter) or #3 the feedback mechanism the computer uses to meter the air fuel ratio( the oxygen sensor in the exhaust) is not getting the computer accurate information(more common). It gets pretty complicated. It gets even more complicated without a lot of expensive tools.
Let's try the simple easy stuff first.
1. Since we played with the air filter let's check the intake boot to the throttle body from the air filter make sure the air filter is secured that boot is intact and there are no leaks in it and all the vacuum hoses going to it or connected properly and the clamps are tight. The mass airflow sensor located in the air filter housing is one of the primary sensors for the engines air fuel ratio. It basically is telling the computer how much air is coming in the vehicle. If that's all good let's move the Step 2
Step2 requires a propane torch. The type you use to solder pipes in your house and heat up small parts. With the engine idling and the air filter housing opened a little bit turn the propane torch on without lighting it sticking the tip of the torch into the air box there for the propane is being sucked into the intake during idle. While doing this look at the long-term fuel trim. It should come back down look at the O2 sensor readings they should be higher than normal. If you don't get these expected responses from your computer data suspect the oxygen sensor. If you do get the expected responses then we got to look as to how it's getting fuel into the air fuel mixture that it shouldn't be. Let me know how it goes

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Motzking1 · 07-16-2017, 05:45 PM

Wait a minute. I mis stated that. You should see your long term fuel trim go more negatively and your O2 sensor voltage go higher than normal. Sorry

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Motzking1 · 07-16-2017, 05:47 PM

Don't replace any parts yet. Depending on the results we may have to pull a few more tricks to be posative of where the problem is.

Sent from my SAMSUNG-SM-N900A using Tapatalk

ojeysky · 05-31-2018, 04:12 AM

Quote:

Originally Posted by Motzking1

Your long term fuel trim number of -14.8 is way, way off. Far enough in the USA that it would trigger a check engine light. It's posible to be an air filter but it would have to be the most plugged air filter I have ever seen in my life! I live in Seattle WA so the air is crystal clear (because it rains, and rains, and rains and rains) I have 100k miles on my air filter and it flows fine. Do you live in a dusty or dirty environment?

Sent from my SAMSUNG-SM-N900A using Tapatalk

Hello,

I am experiencing exactly the above and my fuel consumption has been quite bad as i now do about 200miles on full tank! I am attaching log of my bluedriver scan result, will appreciate pointers on what could be the cause of this. I have checked for vacuum leaks but found none.
Thanks

ojeysky · 06-16-2018, 02:20 AM

Any response, am still get a bad milage. Vehicle is 2010 Yaris sedan AT with post cat 02 sensor recently changed.

07-13-2017, 06:22 AM	#1
grvdggr Drives: Yaris 1.0 -00 Join Date: Sep 2015 Location: Sweden Posts: 4	Torque Pro MAF and other values at idle Hello. I have lost some acceleration and my car is consuming about 0.1 l/100 km more than before. I post my Tourque Pro values in hope that I can compare my values to someone with a well functioning Yaris. I have a 3 door 2000 model with the 1.0 engine. Coolant: 85C Idle revs: 600 rpm MAF: 1,3 g/s STFT: Alternating between 0-3,1% (Short Term Fuel Trim) LTFT: -14,8% (Long Term Fuel Trim) O2x1: Jumping between 0-0,8 V O2x2: 0 V Vacuum: 22,9 in/Hg I have cleaned the MAF thouroghly a week before the test. If you can't compare, is there anything about these numbers that doesn't seem normal? Thanks.

07-13-2017, 07:10 AM	#2
tmontague View User's Garage Drives: '08 2zr swapped Vios M/T Join Date: Oct 2012 Location: Caledonia Ont. Posts: 2,938	Your left's show a potential vacuum leak, I'd check that first __________________ No one ever wants to give a Yaris the point by...

07-15-2017, 07:03 AM	#3
bronsin Drives: 2009 Base Hatch 2 Dr Auto Join Date: Dec 2008 Location: nj Posts: 4,790	Air filter change interval is more like 50,000 km. Under normal operating conditions. __________________ Synthetic Oil: Its All In Your Head

07-16-2017, 04:14 PM	#4
Motzking1 Drives: 47 2013 yaris l hatchbacks Join Date: Nov 2016 Location: Renton, wa Posts: 64	Your long term fuel trim number of -14.8 is way, way off. Far enough in the USA that it would trigger a check engine light. It's posible to be an air filter but it would have to be the most plugged air filter I have ever seen in my life! I live in Seattle WA so the air is crystal clear (because it rains, and rains, and rains and rains) I have 100k miles on my air filter and it flows fine. Do you live in a dusty or dirty environment? Sent from my SAMSUNG-SM-N900A using Tapatalk

07-16-2017, 05:20 PM	#5
grvdggr Drives: Yaris 1.0 -00 Join Date: Sep 2015 Location: Sweden Posts: 4	I drove my Yaris about 300+ km today and the air filter didn't solve the issue as I first thought. =( Still slow acceleration, loses speed in some uphills. My Long Term Fuel Trim has bad values, what could be causing the issue? I've read about the EGR Valve, does a petrol 2000 Yaris have one?

07-16-2017, 05:40 PM	#6
Motzking1 Drives: 47 2013 yaris l hatchbacks Join Date: Nov 2016 Location: Renton, wa Posts: 64	In the USA pretty much every car since 1978 have them. I assume your does. Let's think about this. The computer thinks it needs to put less fuel into the engine than would otherwise be needed for normal operation. There are 3 reasons why this could be. #1 fuel is entering the air/fuel mixture from somewhere it should not be. (Example leaking fuel injector, leaking fuel pressure regulator)[this is not common] #2 there is less air entering the engine therefore requiring the engine to require less fuel.(example a restricted air filter) or #3 the feedback mechanism the computer uses to meter the air fuel ratio( the oxygen sensor in the exhaust) is not getting the computer accurate information(more common). It gets pretty complicated. It gets even more complicated without a lot of expensive tools. Let's try the simple easy stuff first. 1. Since we played with the air filter let's check the intake boot to the throttle body from the air filter make sure the air filter is secured that boot is intact and there are no leaks in it and all the vacuum hoses going to it or connected properly and the clamps are tight. The mass airflow sensor located in the air filter housing is one of the primary sensors for the engines air fuel ratio. It basically is telling the computer how much air is coming in the vehicle. If that's all good let's move the Step 2 Step2 requires a propane torch. The type you use to solder pipes in your house and heat up small parts. With the engine idling and the air filter housing opened a little bit turn the propane torch on without lighting it sticking the tip of the torch into the air box there for the propane is being sucked into the intake during idle. While doing this look at the long-term fuel trim. It should come back down look at the O2 sensor readings they should be higher than normal. If you don't get these expected responses from your computer data suspect the oxygen sensor. If you do get the expected responses then we got to look as to how it's getting fuel into the air fuel mixture that it shouldn't be. Let me know how it goes Sent from my SAMSUNG-SM-N900A using Tapatalk

07-16-2017, 05:45 PM	#7
Motzking1 Drives: 47 2013 yaris l hatchbacks Join Date: Nov 2016 Location: Renton, wa Posts: 64	Wait a minute. I mis stated that. You should see your long term fuel trim go more negatively and your O2 sensor voltage go higher than normal. Sorry Sent from my SAMSUNG-SM-N900A using Tapatalk

07-16-2017, 05:47 PM	#8
Motzking1 Drives: 47 2013 yaris l hatchbacks Join Date: Nov 2016 Location: Renton, wa Posts: 64	Don't replace any parts yet. Depending on the results we may have to pull a few more tricks to be posative of where the problem is. Sent from my SAMSUNG-SM-N900A using Tapatalk

06-16-2018, 02:20 AM	#10
ojeysky Drives: Sedan Yaris 2010 Join Date: Dec 2017 Location: Nigeria Posts: 54	Any response, am still get a bad milage. Vehicle is 2010 Yaris sedan AT with post cat 02 sensor recently changed.