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Topic: "Open loop" fuel system status (Read 1817 times) |
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Ivan Pevnitsky
Full Member
Scorpio Ghia '96, 2.3, Auto
Posts: 172
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"Open loop" fuel system status
« on: Jul 30th, 2009, 3:42pm » |
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Hi there again!
I've got an error P0171 System too lean, and my car is working in "Open loop" mode (i don't know what exactly it is, but I know it's not good  )
I was told by a mechanic that there's no second lamda sensor somewhere either after catalyst or before -i don't remember. But he meant not the one under the hood.
Here my results from ScanXL ELM (click to view fullsize image):
Note that it shows me 2 sensors: bank1 sensor1 (that works) and bank1 sensor2 - that is always 0V. And that is why I think my system works in "open loop" mode.
And I think the reason is abroken lambda sensor. Am I correct?
Thanks
PS: don't pay attention to "Taurus 3.0" at the bottom. It's because the program doesn't support Scorpio, so I had to select another car.
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Gazza_UK
Full Member
2.3 Ultima auto :-)
Posts: 166
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Re: "Open loop" fuel system status
« Reply #1 on: Jul 30th, 2009, 4:13pm » |
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How can it work ?
It cant its looking for features on your car that dont exist ? Like bank 2?
What I mean is it was set up for a 3lt by the sounds of it and yours is a 2.3
To be honest all the readings could be wrong
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scorpio_man
Administrator
Ford Kuga awd
Posts: 5654
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Re: "Open loop" fuel system status
« Reply #2 on: Jul 30th, 2009, 4:20pm » |
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hi there
i'll jump about a bit with my answer.
no, you only have 1 (pre cat) lambda sensor.
how long was the car running before doing the scan? the car needs to be running for 180 seconds before the lambda controls the fueling (closed loop).
your long term fuel trim is high at 18%.
was it really warm outside when you ran the scan, as your intake air temp sensor is at 46oC! remember the intake can get warmer than outside temp (maybe +10 oC).
at a quess, i'd think you have a air/vacuum leak somewhere (egr pipework?).
hth
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tlundkvi
Full Member
Ex. Scorpio 2.9 24V -95
Posts: 909
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Re: "Open loop" fuel system status
« Reply #3 on: Jul 30th, 2009, 7:07pm » |
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on Jul 30th, 2009, 4:13pm, Gazza_UK wrote:
How can it work ?
It cant its looking for features on your car that dont exist ? Like bank 2?
What I mean is it was set up for a 3lt by the sounds of it and yours is a 2.3
To be honest all the readings could be wrong
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There is one bank and two sensors mentioned in the post. Sensor 2 is mounted after the cat and should show a steady line between 0.4 and 0.5 Volt, used for monitoring only. If jumping => bad cat. Reading of 0V suggests a bad lambda sensor, but still the sensor 2 only monitors. Ivan, are there any other error codes? Have you done an exhaust test?
I believe the Taurus 3.0 was needed to setup the right communication protocol. I may be wrong, but I believe the ODB-stuff can query which sensors and codes exist (like plug & play). My 24V could be scanned with the settings for a 2.0 which is different too, and yet codes & info about second bank lambdas was readily shown.
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scorpio_man
Administrator
Ford Kuga awd
Posts: 5654
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Re: "Open loop" fuel system status
« Reply #4 on: Jul 30th, 2009, 9:36pm » |
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hi there
as i said earlier, the 2.3 DOES NOT have a 2nd lambda, only a PRE cat lambda.
the 'reading' is at 0 volts as it's not there.
hth
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Gazza_UK
Full Member
2.3 Ultima auto :-)
Posts: 166
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Re: "Open loop" fuel system status
« Reply #5 on: Jul 31st, 2009, 12:20am » |
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on Jul 30th, 2009, 7:07pm, tlundkvi wrote:
Sensor 2 is mounted after the cat.
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Not on a 2.3 
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tlundkvi
Full Member
Ex. Scorpio 2.9 24V -95
Posts: 909
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Re: "Open loop" fuel system status
« Reply #6 on: Jul 31st, 2009, 8:31am » |
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Sorry, my mistake 
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Ivan Pevnitsky
Full Member
Scorpio Ghia '96, 2.3, Auto
Posts: 172
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Re: "Open loop" fuel system status
« Reply #7 on: Jul 31st, 2009, 6:12pm » |
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Sorry me, guys ) It was an old info about the problem.
I have recently changed EGR pipe (because it's been broken), and idle revs became stable. But I believed that P0171 stayed.
Today I checked my car again. And there were no P0171 code (there're only gearbox related ones)
And here's a pic (click on it to enlarge):
Forget to check fuel system status though, but i think it should be ok! Will check it later.
And thank you for the info that there's only one lambda sensor. I can sleep calmly now )
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scorpio_man
Administrator
Ford Kuga awd
Posts: 5654
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Re: "Open loop" fuel system status
« Reply #8 on: Aug 1st, 2009, 7:56am » |
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hi there
that scan seems far better.
are you running a induction kit on the air filter? your intake air temperature is still quite high (or is it really warm outside).
also, your MAF readings are a wee bit low. maybe run a scan on just that and check the readings throughout the rev range? 
hth
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Ivan Pevnitsky
Full Member
Scorpio Ghia '96, 2.3, Auto
Posts: 172
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Re: "Open loop" fuel system status
« Reply #9 on: Aug 2nd, 2009, 10:05am » |
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I don't know what is the induction kit.
The air temperature was about 23° Celsuis with almost no wind. How much should be IAT? Where's the temperature IAT sensor?
How much should be MAF data? I have recently changed air filter and cleaned the MAF. I'll try to test it on higher revs, and even while driveng
Thanks
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scorpio_man
Administrator
Ford Kuga awd
Posts: 5654
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Re: "Open loop" fuel system status
« Reply #10 on: Aug 2nd, 2009, 11:21am » |
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hi there
the clear air filter and MAF will explain the lower readings.
an induction kit is something like using a K&N cone instead of the filter box.
the IAT sensor is underneath the air tube to the throttle. you can give it a clean with carb cleaner.
hth
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Gazza_UK
Full Member
2.3 Ultima auto :-)
Posts: 166
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Re: "Open loop" fuel system status
« Reply #11 on: Aug 2nd, 2009, 2:47pm » |
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on Aug 2nd, 2009, 11:21am, scorpio_man wrote:the IAT sensor is underneath the air tube to the throttle. you can give it a clean with carb cleaner.
hth |
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Please show by Pic if possable as Im curios on this and what it does ( see im still learning as well )
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Gazza_UK
Full Member
2.3 Ultima auto :-)
Posts: 166
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Re: "Open loop" fuel system status
« Reply #13 on: Aug 3rd, 2009, 4:28pm » |
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Is there any info on what theses all do ?
EDIT
the ones I DONT know and what they do are
A
B
C
D
I
J
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scorpio_man
Administrator
Ford Kuga awd
Posts: 5654
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Re: "Open loop" fuel system status
« Reply #14 on: Aug 3rd, 2009, 4:45pm » |
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hi there
a= idle by pass valve.
b= throttle postion sensor.
c= only on the 2.0 16v and 2.9 24v engines.
d= camshaft sensor.
i= engine coolant temperature sensor.
j= intake air temperature sensor.
http://www.fordscorpio.co.uk/ccmonitor.htm
hth
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Ivan Pevnitsky
Full Member
Scorpio Ghia '96, 2.3, Auto
Posts: 172
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Re: "Open loop" fuel system status
« Reply #15 on: Aug 3rd, 2009, 10:25pm » |
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why the letters on the picture end with H, J, K . while the description ends with H, I, J
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Gazza_UK
Full Member
2.3 Ultima auto :-)
Posts: 166
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Re: "Open loop" fuel system status
« Reply #16 on: Aug 4th, 2009, 10:39am » |
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Well spoted just noticed that my self
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Gazza_UK
Full Member
2.3 Ultima auto :-)
Posts: 166
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Re: "Open loop" fuel system status
« Reply #17 on: Aug 4th, 2009, 10:58am » |
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on Aug 3rd, 2009, 4:45pm, scorpio_man wrote:
Yes thats what Im after . . .
now it can make some sense to me
Right with that Info I'm off to mates garage to play with is Snap On ETHOS
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Ivan Pevnitsky
Full Member
Scorpio Ghia '96, 2.3, Auto
Posts: 172
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Re: "Open loop" fuel system status
« Reply #18 on: Aug 8th, 2009, 3:52pm » |
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Took a diagram while 10 minutes driving:
2scorpio_man: see that IAT's falling down from 50° to 23° while driving (the outer air temperature was about 13.5°).
Why the MAP is alwas 0? Is it failed MAP signal?
There're no MAP-related errors in my DTCs, they are only gearbox-related:
P0732 Gear 2 Incorrect Ratio
P1756 Shift Solenod B Performance
P1761 Shift Solenod C Performance
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Tompion
Administrator
1997 2.3 Ultima estate.
Posts: 2918
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Re: "Open loop" fuel system status
« Reply #19 on: Aug 8th, 2009, 7:00pm » |
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Assuming the MAP referred to is a sensor then there isn’t one, it was superseded by the MAF.
See first paragraph here:
http://www.fordscorpio.co.uk/cleanmaf.htm
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ABS multiplug wheel sensor pins MK IV or MK 20
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