Little Help with my OBD
Joined: Feb 2014
Posts: 20,479
Likes: 15,252
From: Crossroads of America
The IAT sensor can be verified against the chart on page 86 of the Jaguar 801S doc . So for 68 F it should read 2500 ohms . 86 F is 1700 ohms . It is a thermister .
An open wire or bad connector mimics a cold reading .
It's the exact same as the 2 wire ECT sensor .
An open wire or bad connector mimics a cold reading .
It's the exact same as the 2 wire ECT sensor .
Just for clarity, what you mean is that the resistance vs. temperature readings of the IAT and ECT are the same, not that the two sensors are the same part, right?
Cheers,
Don
Veteran Member
Joined: Apr 2017
Posts: 4,039
Likes: 1,397
From: Kansas City USA
I'll need to double check later as I'm on my way out to the salvage yards looking for some wonderful things so M'Lady Penelope feels whole again . She likes it when I bring her shiny things like X308 headlights and chrome mirrors and handles . Why do I do such things for her , because she's special . just ask her .
Last edited by Lady Penelope; May 2, 2018 at 11:04 AM.
Veteran Member
Joined: Apr 2017
Posts: 4,039
Likes: 1,397
From: Kansas City USA
[QUOTE=cdma;1888131]Here are my latest readings.....anything looking out of wack?
IAT is high 55 C / 131 F
MAF is off by a factor of 100 , common device error
In closed loop mode your O2 sensors should be reading .
IAT is high 55 C / 131 F
MAF is off by a factor of 100 , common device error
In closed loop mode your O2 sensors should be reading .
Thread Starter
|
Senior Member
Joined: Dec 2013
Posts: 856
Likes: 276
From: Albuquerque, NM
I guess I will replace my IAT from the parts car. Just was not sure it was necessary. Not sure why O2 was not reading. When I did a diag it said that they were in spec. Maybe for some reason when I ran the PID scanner it did not get the data. I hope you are right about the MAF. I just replaced it from my parts car unless that one was bad.
Veteran Member
Joined: Apr 2017
Posts: 4,039
Likes: 1,397
From: Kansas City USA
You can read the MAF another way with the Green / Pink wire reading 1.2 volts DC at idle and going toward but not too the reference 5.0 volts on throttle up . The IAT is a factor in fuel trim along with ECT .
Last edited by Lady Penelope; May 2, 2018 at 11:43 AM.
Thread Starter
|
Senior Member
Joined: Dec 2013
Posts: 856
Likes: 276
From: Albuquerque, NM
SO if closed loop is not right what should I be looking at to determine the issue. Again still having MPG issues. Since I have the extra car I have been swapping out different part. However, as suggested, I am running a trail to see who close my MPG gauge is to the actual MPG's. Maybe I have an issues with the gauge.
Two other things. I am going to change out the Coolant temp Sensor tonight and I know that I do have an exhaust leak and will be changing out the manifold as soon as the gasket come in
Two other things. I am going to change out the Coolant temp Sensor tonight and I know that I do have an exhaust leak and will be changing out the manifold as soon as the gasket come in
Last edited by cdma; May 2, 2018 at 02:00 PM.
Veteran Member
Joined: Apr 2017
Posts: 4,039
Likes: 1,397
From: Kansas City USA
Plugged in and engine running pulling air . TPS just with key on not running . You can take a needle on the back end of the connector or strip some insulation off the wire as it goes over the fuel rail . I sodiered in test leads for easy reading in service .
Joined: Feb 2014
Posts: 20,479
Likes: 15,252
From: Crossroads of America
I don’t think it means anything, but Anytime I see “Closed Loop”, I give it the stink eye.
Fuel System is Closed Loop? Does that mean the fueling system is in Closed Loop? If it does, then there’s something that’s preventing the ECU from wanting to read the sensors for fueling.
Fuel System is Closed Loop? Does that mean the fueling system is in Closed Loop? If it does, then there’s something that’s preventing the ECU from wanting to read the sensors for fueling.
I'm not following you, Vee. Closed loop means the ECM is actively monitoring the sensors and dynamically adjusting fuel metering (injector pulse duration) to maintain the air-to-fuel ratio (AFR) at stoichiometric, instead of fueling based on default maps (open loop) as it does while it's waiting for the O2S heaters to bring them to operating temperature.
Am I missing something?
Cheers,
Don
Last edited by Don B; May 2, 2018 at 10:48 PM.
Veteran Member
Joined: May 2010
Posts: 5,332
Likes: 1,742
From: Arlington, VA
Dammit, I switched the two in my head.
now I’m really puzzled. All if your readings look great.
I expected Long Term Fuel Trim to be out of bounds, but at just under 1%, it’s fuelling just fine.
now I’m really puzzled. All if your readings look great.
I expected Long Term Fuel Trim to be out of bounds, but at just under 1%, it’s fuelling just fine.
Thread Starter
|
Senior Member
Joined: Dec 2013
Posts: 856
Likes: 276
From: Albuquerque, NM
This weekend took the car on a long trip just to check the tripmeter and ensure that the milage that it had on the display actually matched to real world. (Also played a little golf 
) Well the were almost dead on. I would say 90% of the milage this weekend came from Highway driving. I averaged 22.1 MPGs. Seems pretty crappy? Checked all the fault logs and there were no issues. Everything seemed to be running clean. Is 22.1 normal and what else could I check. It does still say I am running rich but I will be changing out the manifold this week and looking for any other leaks.
) Well the were almost dead on. I would say 90% of the milage this weekend came from Highway driving. I averaged 22.1 MPGs. Seems pretty crappy? Checked all the fault logs and there were no issues. Everything seemed to be running clean. Is 22.1 normal and what else could I check. It does still say I am running rich but I will be changing out the manifold this week and looking for any other leaks.
Veteran Member
Joined: May 2010
Posts: 5,332
Likes: 1,742
From: Arlington, VA
22.1 is normal.
If I cruised on a freeway with out having to make any stops, I should be able to get to the mid, or maybe even high 20s. Any stops in town, or taking an exit would immediately plummet that back towards the lower 20s.
If I cruised on a freeway with out having to make any stops, I should be able to get to the mid, or maybe even high 20s. Any stops in town, or taking an exit would immediately plummet that back towards the lower 20s.
Thread
Thread Starter
Forum
Replies
Last Post
thedicktator
S-Type / S type R Supercharged V8 ( X200 )
5
Oct 30, 2010 09:59 PM
patrickw813
PRIVATE For Sale / Trade or Buy Classifieds
7
Mar 3, 2010 08:11 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)