Please help interpret live data-rough idle
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Posting Guru
Joined: Dec 2002
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From: Billings MT
Please help interpret live data-rough idle
Fuel sys1. CL
Calc load. 32.2
ECT. 194
STFT B1. -1.6
LTFT B1. 9.4
STFT B2 -2.3
LFTF B2. 8.6
Spark Adv 30
IAT 111
MAF 1.1
TPS 19.6
O2S B1 S1. .08-.72
STFT B1S1 -2.3 to 1.0
O2S B3 S1 .075-.770
STFT B3 S1 -3.1 to 3.1
Any thought? I've replaced PCV line and elbows, can see the EGR valve move, fuel economy is horrid.
Thanks
Calc load. 32.2
ECT. 194
STFT B1. -1.6
LTFT B1. 9.4
STFT B2 -2.3
LFTF B2. 8.6
Spark Adv 30
IAT 111
MAF 1.1
TPS 19.6
O2S B1 S1. .08-.72
STFT B1S1 -2.3 to 1.0
O2S B3 S1 .075-.770
STFT B3 S1 -3.1 to 3.1
Any thought? I've replaced PCV line and elbows, can see the EGR valve move, fuel economy is horrid.
Thanks
New User
Joined: Apr 2016
Posts: 9
Likes: 0
A couple of things jump out at me. Hope this helps.
Engine coolant temp is good if the engine really has had time to warm up completely.
These look ok
I wouldn't expect such an advanced spark at idle but might be okay if it's not rattling and pinging at an idle.
This is your intake air temperature. 111 degrees?? Holy crap.. I suspect your MAF sensor is getting bad information. Intake air temp is read from the mass air flow sensor in line with the intake.
This to me looks questionable. Your throttle (TPS) shows to be open but your Mass Air Flow reading is incredibly low.
Long term and short term fuel trims look ok.
Based on this data and my experience with the 5.4 and 4.6 engines, I would say your mas air flow sensor is covered in goo, or is completely failing. Just take it out of the intake air tube and clean it. If that doesn't fix it, then you can replace it. It's probably running very lean at the moment, has no get up and go, and as you said gets crap for mileage.
Engine coolant temp is good if the engine really has had time to warm up completely.
These look ok
I wouldn't expect such an advanced spark at idle but might be okay if it's not rattling and pinging at an idle.
This is your intake air temperature. 111 degrees?? Holy crap.. I suspect your MAF sensor is getting bad information. Intake air temp is read from the mass air flow sensor in line with the intake.
This to me looks questionable. Your throttle (TPS) shows to be open but your Mass Air Flow reading is incredibly low.
Long term and short term fuel trims look ok.
Based on this data and my experience with the 5.4 and 4.6 engines, I would say your mas air flow sensor is covered in goo, or is completely failing. Just take it out of the intake air tube and clean it. If that doesn't fix it, then you can replace it. It's probably running very lean at the moment, has no get up and go, and as you said gets crap for mileage.
Thread Starter
|
Posting Guru
Joined: Dec 2002
Posts: 1,297
Likes: 3
From: Billings MT
A couple of things jump out at me. Hope this helps.
Engine coolant temp is good if the engine really has had time to warm up completely.
These look ok
I wouldn't expect such an advanced spark at idle but might be okay if it's not rattling and pinging at an idle.
This is your intake air temperature. 111 degrees?? Holy crap.. I suspect your MAF sensor is getting bad information. Intake air temp is read from the mass air flow sensor in line with the intake.
This to me looks questionable. Your throttle (TPS) shows to be open but your Mass Air Flow reading is incredibly low.
Long term and short term fuel trims look ok.
Based on this data and my experience with the 5.4 and 4.6 engines, I would say your mas air flow sensor is covered in goo, or is completely failing. Just take it out of the intake air tube and clean it. If that doesn't fix it, then you can replace it. It's probably running very lean at the moment, has no get up and go, and as you said gets crap for mileage.
Engine coolant temp is good if the engine really has had time to warm up completely.
These look ok
I wouldn't expect such an advanced spark at idle but might be okay if it's not rattling and pinging at an idle.
This is your intake air temperature. 111 degrees?? Holy crap.. I suspect your MAF sensor is getting bad information. Intake air temp is read from the mass air flow sensor in line with the intake.
This to me looks questionable. Your throttle (TPS) shows to be open but your Mass Air Flow reading is incredibly low.
Long term and short term fuel trims look ok.
Based on this data and my experience with the 5.4 and 4.6 engines, I would say your mas air flow sensor is covered in goo, or is completely failing. Just take it out of the intake air tube and clean it. If that doesn't fix it, then you can replace it. It's probably running very lean at the moment, has no get up and go, and as you said gets crap for mileage.
I've replaced the MAF, the old one was cleaned and gave the same values as the new one. The new one is a Ford part, not aftermarket. It was only about 60 degrees outside when I ran those codes.
New User
Joined: Apr 2016
Posts: 9
Likes: 0
Is this an older engine? What year is it? Unless it's an older engine the MAF and IAT have been modular for some time. If the sensor has been replaced, you feel confident it is good, then start checking your wiring on the sensor. It's got to be somewhere near the MAF, (or if it's a separate sensor the IAT)
Thread Starter
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Posting Guru
Joined: Dec 2002
Posts: 1,297
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From: Billings MT
If it were 60 outside, I really don't know how in the world you would get an IAT reading much higher than that. I've never had any of mine be more than 10 degrees above ambient temperature, unless your intake ducting is shortened beyond stock.
Is this an older engine? What year is it? Unless it's an older engine the MAF and IAT have been modular for some time. If the sensor has been replaced, you feel confident it is good, then start checking your wiring on the sensor. It's got to be somewhere near the MAF, (or if it's a separate sensor the IAT)
Is this an older engine? What year is it? Unless it's an older engine the MAF and IAT have been modular for some time. If the sensor has been replaced, you feel confident it is good, then start checking your wiring on the sensor. It's got to be somewhere near the MAF, (or if it's a separate sensor the IAT)
Hotshot
Joined: Jan 2004
Posts: 19,763
Likes: 1,082
From: St Louis
Your throttle (TPS) shows to be open but your Mass Air Flow reading is incredibly low.
FWIW, there's absolutely nothing in that live data that I can see that would account for a rough idle. I'd investigate fuel quality, fuel pressure/delivery, unaccounted-for misfires, or unwanted EGR flow. I'd also get a much more complete set of symptoms besides just "rough idle" and poor fuel economy because I suspect there's way more to the story than has been told.
Thread Starter
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Posting Guru
Joined: Dec 2002
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From: Billings MT
Normal TPS position at idle is around 20%. It should never go (much) below that.
FWIW, there's absolutely nothing in that live data that I can see that would account for a rough idle. I'd investigate fuel quality, fuel pressure/delivery, unaccounted-for misfires, or unwanted EGR flow. I'd also get a much more complete set of symptoms besides just "rough idle" and poor fuel economy because I suspect there's way more to the story than has been told.
FWIW, there's absolutely nothing in that live data that I can see that would account for a rough idle. I'd investigate fuel quality, fuel pressure/delivery, unaccounted-for misfires, or unwanted EGR flow. I'd also get a much more complete set of symptoms besides just "rough idle" and poor fuel economy because I suspect there's way more to the story than has been told.
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Thread Starter
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Posting Guru
Joined: Dec 2002
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From: Billings MT
Thanks. In down to a stuck EGR. I don't see it moving up and down. I graphed the two O2 sensors and one is fairly stable wave and the other one has about 4-5 times the activity. Those are next after EGR. It idles great when cold, but as it warms up, the idle gets rough. It sounds like it has a fairly aggressive RV cam in it. I don't how else to describe it. You can smell fuel and it's definitely running rich and loading up on fuel.
It was a stuck EGR valve. Replaced it tonight, idles great again.
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Rough Idle, intermittent Stalling
Good morning all,
I have a 2002 Ford Explorer with the 4.6lt. Recently, it has been idling rough and low, around 500RPM. It will also stall occasionally at idle, however it starts immediately afterwards. I have replaced the spark plugs, however the fault remains. I am about to replace the fuel filter and I will be cleaning the throttle body as well. I have no engine fault lights or codes.
Attached is the last data grab from a recent trip (OBD). I am not too sure what I'm looking at, so if anyone is able to have a quick look and advise any abnormalities - that would be greatly appreciated.
Thanks in advance.
Peter.
I have a 2002 Ford Explorer with the 4.6lt. Recently, it has been idling rough and low, around 500RPM. It will also stall occasionally at idle, however it starts immediately afterwards. I have replaced the spark plugs, however the fault remains. I am about to replace the fuel filter and I will be cleaning the throttle body as well. I have no engine fault lights or codes.
Attached is the last data grab from a recent trip (OBD). I am not too sure what I'm looking at, so if anyone is able to have a quick look and advise any abnormalities - that would be greatly appreciated.
Thanks in advance.
Peter.
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