Comparing Data
#21
Well, as I said in another post a while back, I'm always glad to help folks who appreciate the assistance. Attached is an archive of the ScanXL layouts I've toiled over during the last few years. Bare in mind that I'm into diagnostics and not tuning, so these are not really "dashboards". They are functional layouts I use in diagnosing driveability issues or confirming repairs. They would be usable in ScanXL or PCMScan, both available from Palmer Performance.
I hope some of you find them helpful!
Cheers,
I hope some of you find them helpful!
Cheers,
#25
Go to the Dashboards Tab, at the bottom is the Classic Dashboard button, click it. In the window that pops up, name the new Tab whatever you want, and a new Tab is created. In the new tab is a Load Layout button [top left, folder], click it and navigate to the folder you have my layouts in and select one.
Voila!! A new world awaits!
Cheers,
Voila!! A new world awaits!
Cheers,
#27
#28
???
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aholbro1 (05-15-2011)
#29
If the codes show up on the 03, I'll concentrate on the MAFS. If not, I reckon I'll move on to the next thing. Ordered a fuel cap for the 05 last week....so now have 3 that fit the 03, only the existing OEM for the 05, so I had to violate the "path of least work" theorem and swap MAFS's
So are fuel trims the response to what the O2 sensors see in the exhaust?
I'm having trouble reconciling lean-codes with neg fuel trims...unless the neg. trim is making it lean, then the codes. Clearly, I don't understand fuel trims (never even heard of 'em until I started spending some time here on the forum) so I'm sure I need to go find that thread from not so long ago where someone linked to a primer on control-systems/fuel trims....
Again, I appreciate your time in looking at it and providing feedback...hoping to learn more, but for now, nice to have confirmation that swapping MAFS maybe the right step.
>>Edit:
Planned to take data on both from cold-start this afternoon, but after loading 6 up for church, Excursion died in the driveway on the way out. Despite successful restart, Wife leary of it, and not wanting to ruin later data-taking, I suggested we take both S-Types (operating temp idle/2500 in lieu of cold-start) which begat endless harrangue's from the wife&daughter 'bout the various atrocities the two li'l kids had visited upon their respective rear seat cupholders...."Sheesh!!" Us lads took the 03 (8 mi, one-way) which is currently sporting the 05 air-box top with included MAFs, and returned home sans codes, beyond the std. P1111.
Just took an idle/2500/idle sample at 0.1 sec intervals and will do likewise with the 05 when it returns.
hmmm...guess maybe beyond that activity...I should rather invest my time in determining what's up with the diesel...it's a bit of a handful once you secure boost assist to the strng and brakes...
>>Edit End
Last edited by aholbro1; 05-15-2011 at 11:28 AM.
#30
More data after swapping MAFS
The girls went to Decatur to hit Taco Bell after church, so the 05 got maybe 8 mi / 15 mi / 5 mi instead of 8 / 8 like the 03. Nonetheless, no codes on it either.
Here are numbers after swapping MAFS and the one originally on the 05 (now fitted to the 03) is definitely more optimistic in its airflow measurements than the other. Still....is there enough here to expect lean codes (P0171/P0174) to eventually pop on the 03? In the past, the 05 would get them maybe once/wk or so, and as mentioned before, sometimes I find only the P0174...but sometimes both. So far, never see the P0171 alone.
Guess I'll run 'em this way till codes show up on one or the other.
Despite the filename...it's all in there, in various tabs, along with some basic calculations I did to try to get my mind around the numbers. Any and all analyses/explanations are welcomed.
Here are numbers after swapping MAFS and the one originally on the 05 (now fitted to the 03) is definitely more optimistic in its airflow measurements than the other. Still....is there enough here to expect lean codes (P0171/P0174) to eventually pop on the 03? In the past, the 05 would get them maybe once/wk or so, and as mentioned before, sometimes I find only the P0174...but sometimes both. So far, never see the P0171 alone.
Guess I'll run 'em this way till codes show up on one or the other.
Despite the filename...it's all in there, in various tabs, along with some basic calculations I did to try to get my mind around the numbers. Any and all analyses/explanations are welcomed.
#31
It's a little hard to sift through all the raw data like that, but it appears to me that the high negative fuel trims have in fact moved to the 2003 car. But it also seems there are now some high positive fuel trims that remain with the 2005; that could explain the lean codes. Who knows, with an errant MAF out of the picture, you may find it easier to track down a possible air leak in the 2005.
You are right to have trouble reconciling negative trims with lean faults, that's why you need to have data from different operating ranges to put together a whole picture. With that you can address what you know [fix one problem you've proven], then reassess the system and move on.
You mentioned reading of my fuel trim primer, below is a link to that thread. You can thank h20boy, he's that one that started that snowball rolling!
https://www.jaguarforums.com/forum/g...ed-quiz-49317/
You're on the right track.........just follow the data.
Good luck!
You are right to have trouble reconciling negative trims with lean faults, that's why you need to have data from different operating ranges to put together a whole picture. With that you can address what you know [fix one problem you've proven], then reassess the system and move on.
You mentioned reading of my fuel trim primer, below is a link to that thread. You can thank h20boy, he's that one that started that snowball rolling!
https://www.jaguarforums.com/forum/g...ed-quiz-49317/
You're on the right track.........just follow the data.
Good luck!
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aholbro1 (05-15-2011)
#32
Seems to me you're spending time gathering too much data and with no plan.
I found it too hard to look at but if you mean LTFTs of around -3 they're not significantly far from 0 so probably best treated as fine - unless something says they're not. (More than +10 or -10 and I'm interested, for sure. Maybe even at +/-7.)
As the trims look OK and aren't varying with revs, move on.
What was the freeze frame data for each code? That will tell you the things going on when the code flagged and also how to go about causing them at will.
And is it fairly consistent?
If you have the time, by all means check each sensor has plausible values - and as you have 2 cars this means you can really cross check.
Pay particular attention to anything listed for your codes in the jag codes PDF. Those items are the ones jag say can cause the codes.
I found it too hard to look at but if you mean LTFTs of around -3 they're not significantly far from 0 so probably best treated as fine - unless something says they're not. (More than +10 or -10 and I'm interested, for sure. Maybe even at +/-7.)
As the trims look OK and aren't varying with revs, move on.
What was the freeze frame data for each code? That will tell you the things going on when the code flagged and also how to go about causing them at will.
And is it fairly consistent?
If you have the time, by all means check each sensor has plausible values - and as you have 2 cars this means you can really cross check.
Pay particular attention to anything listed for your codes in the jag codes PDF. Those items are the ones jag say can cause the codes.
Last edited by JagV8; 05-16-2011 at 01:03 AM.
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aholbro1 (05-16-2011)
#33
John, thanks, I appreciate the input. Perhaps guilty as charged of having no "plan" per se, but really not much time spent gathering data, 5 mins or so, and another 20 constructing functions to take the avg, max and min.
"The Plan" such as it is, and reason for posting here in "comparing data" on the one hand is that Achy covered the P0171/174 fairly extensively as has Gus. On the other hand, one lament at the start of this thread was the incomparibility of various data that may be posted due to differing vehicles/engines/ambient conditions. With 2 3.0L's 2 MY's removed within 10 ft of each other and same ambient conditions, I thought it may contribute to the knowledge base to post near-same-time data. Even more interesting (to me, anyway) that one has a problem that theoretically should be evident in the data. So the plan is to throw the data up there as I take it in hopes someone will post, "Hey....here is your problem...go change this..." but being a bit more realistic, and having my daughter's car home for the summer...I set about the path of least work to swap potentially offending components until I get the codes to switch cars. Alas, the incompatibility of fuel caps killed my first attempt. So now in phase 2 with swapped MAF's...thus far, no code either car....may have to declare "success" order the pizza, celebrate, congratulate the team and move on just like they do at several places I've worked after every abortion of a software implementation that comes along
Steve,
really appreciate the link..that is the one I was thinking of....didn't have the time and mental concentration to read through it when I first saw it. Yesterday...failed the quiz miserably but think I caught-on as soon as I saw the answer - Fuel trims based on O2 data....so all the unburned fuel in the world could be coming from the unplugged-coil cyl. and the system only cares that more oxygen is present on acct. of it didn't get burned when the cyl. didn't fire, thus Positive STFT because it appears "lean" no?
On to my data...the 2005 was sporting long-term FT's in the range of interest to John (-9 to -11 @idle) before I swapped MAF's. Now just below his threshold at -6/-5. However, pre-swap, the 2500 rpm results were significantly lower (+1/+4) but with significant variation (-12/-14 mins and +3/+6 max's) so would sort of indicate the vacuum leak I've missed due to incompetence/carelessness? Less of an impact at 2500? (just thinking out loud) Aahhh..but if so....shouldn't it be even quicker to set the codes after the MAF swap with the MAF now reporting less airflow, thus any leak further magnified?
In any event, a further purpose is I finally "Squeaked" a bit and splurged the $4.95 on paid version of the Droid app "Torque" and simultaneously trying to expand my knowledge of its capabilities and anyway...I'd much rather crunch and massage data amongst the spreadsheet than actually have to go get my hands dirty......May hafta find some funds for AE, though....Excursion proving troublesome and allegedly everything readable if you have the Ford Turbo-dsl add-on...does anyone know if the reported $350 ballpark figure is base AE or does that include either a Jag-specific or other such module? I've seen the same figure tossed about on the diesel board and just curious how much to obtain an AE AND the capability to read my Jag's and my dsl?
hmmm...not sure I have the capability to obtain "freeze-frame" data?
"The Plan" such as it is, and reason for posting here in "comparing data" on the one hand is that Achy covered the P0171/174 fairly extensively as has Gus. On the other hand, one lament at the start of this thread was the incomparibility of various data that may be posted due to differing vehicles/engines/ambient conditions. With 2 3.0L's 2 MY's removed within 10 ft of each other and same ambient conditions, I thought it may contribute to the knowledge base to post near-same-time data. Even more interesting (to me, anyway) that one has a problem that theoretically should be evident in the data. So the plan is to throw the data up there as I take it in hopes someone will post, "Hey....here is your problem...go change this..." but being a bit more realistic, and having my daughter's car home for the summer...I set about the path of least work to swap potentially offending components until I get the codes to switch cars. Alas, the incompatibility of fuel caps killed my first attempt. So now in phase 2 with swapped MAF's...thus far, no code either car....may have to declare "success" order the pizza, celebrate, congratulate the team and move on just like they do at several places I've worked after every abortion of a software implementation that comes along
Steve,
really appreciate the link..that is the one I was thinking of....didn't have the time and mental concentration to read through it when I first saw it. Yesterday...failed the quiz miserably but think I caught-on as soon as I saw the answer - Fuel trims based on O2 data....so all the unburned fuel in the world could be coming from the unplugged-coil cyl. and the system only cares that more oxygen is present on acct. of it didn't get burned when the cyl. didn't fire, thus Positive STFT because it appears "lean" no?
On to my data...the 2005 was sporting long-term FT's in the range of interest to John (-9 to -11 @idle) before I swapped MAF's. Now just below his threshold at -6/-5. However, pre-swap, the 2500 rpm results were significantly lower (+1/+4) but with significant variation (-12/-14 mins and +3/+6 max's) so would sort of indicate the vacuum leak I've missed due to incompetence/carelessness? Less of an impact at 2500? (just thinking out loud) Aahhh..but if so....shouldn't it be even quicker to set the codes after the MAF swap with the MAF now reporting less airflow, thus any leak further magnified?
In any event, a further purpose is I finally "Squeaked" a bit and splurged the $4.95 on paid version of the Droid app "Torque" and simultaneously trying to expand my knowledge of its capabilities and anyway...I'd much rather crunch and massage data amongst the spreadsheet than actually have to go get my hands dirty......May hafta find some funds for AE, though....Excursion proving troublesome and allegedly everything readable if you have the Ford Turbo-dsl add-on...does anyone know if the reported $350 ballpark figure is base AE or does that include either a Jag-specific or other such module? I've seen the same figure tossed about on the diesel board and just curious how much to obtain an AE AND the capability to read my Jag's and my dsl?
hmmm...not sure I have the capability to obtain "freeze-frame" data?
Last edited by aholbro1; 05-16-2011 at 12:02 PM.
#34
To answer for Steve: you've got it right. All the car can see is O2 via the sensor. It can't see unburnt fuel. So, O2 can be a leak or a misfire or just a bit of variation i.e. a small bit more O2 than expected will be plausible and the fuel trims will be adjusted. If lots of adjustment is needed then it tends to throw P0171/P0174.
Misfires are detected by seeing tiny variations that shouldn't be there in the crankshaft signal CKP. That's why the PCM has to learn what a good CKP looks like as part of the drive cycle - done by coast-downs i.e. slowing from about 50mph without braking.
Any form of excess O2 will make LTFT positive (i.e. adding fuel to compensate for the excess O2).
If the LTFT stays about the same at 2500rpm as at idle you almost for sure don't have an air leak. Or: you do but it's intermittent and your data hasn't captured it.
The freeze frame data can be very helpful (or useless LOL), especially if it happens to be rather similar each time.
-ve LTFTs can be quite a few things (such as misreporting MAF or wrong fuel pressure/sensor or even dribbling injectors). Together with lean codes? hmm, not sure.
I got AE with jag extras but not Ford extras and it was about $450. I doubt you need it for your current problem (but it's cool stuff).
They offered a cheaper combined deal of base+Ford at the time (but not a cheaper base+jag) so have a good look at what's on offer if you do decide to buy.
Misfires are detected by seeing tiny variations that shouldn't be there in the crankshaft signal CKP. That's why the PCM has to learn what a good CKP looks like as part of the drive cycle - done by coast-downs i.e. slowing from about 50mph without braking.
Any form of excess O2 will make LTFT positive (i.e. adding fuel to compensate for the excess O2).
If the LTFT stays about the same at 2500rpm as at idle you almost for sure don't have an air leak. Or: you do but it's intermittent and your data hasn't captured it.
The freeze frame data can be very helpful (or useless LOL), especially if it happens to be rather similar each time.
-ve LTFTs can be quite a few things (such as misreporting MAF or wrong fuel pressure/sensor or even dribbling injectors). Together with lean codes? hmm, not sure.
I got AE with jag extras but not Ford extras and it was about $450. I doubt you need it for your current problem (but it's cool stuff).
They offered a cheaper combined deal of base+Ford at the time (but not a cheaper base+jag) so have a good look at what's on offer if you do decide to buy.
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aholbro1 (05-17-2011)
#35
Update:
Still no codes on either S-type since the MAF Swap. I did manage to "fix" the Excursion. Seems the Paid-version of Torque, has the capability to shut the Ford Powerstroke down by sending a "check codes" command to the ELM327 Bluetooth. I recall at least one other member here has a PSD so thought I'd throw it out there.
So now I can get back to the 05 and its issues...
Still no codes on either S-type since the MAF Swap. I did manage to "fix" the Excursion. Seems the Paid-version of Torque, has the capability to shut the Ford Powerstroke down by sending a "check codes" command to the ELM327 Bluetooth. I recall at least one other member here has a PSD so thought I'd throw it out there.
So now I can get back to the 05 and its issues...
#37
To answer for Steve: you've got it right. All the car can see is O2 via the sensor. It can't see unburnt fuel. So, O2 can be a leak or a misfire or just a bit of variation i.e. a small bit more O2 than expected will be plausible and the fuel trims will be adjusted. If lots of adjustment is needed then it tends to throw P0171/P0174.
Misfires are detected by seeing tiny variations that shouldn't be there in the crankshaft signal CKP. That's why the PCM has to learn what a good CKP looks like as part of the drive cycle - done by coast-downs i.e. slowing from about 50mph without braking.
Any form of excess O2 will make LTFT positive (i.e. adding fuel to compensate for the excess O2).
If the LTFT stays about the same at 2500rpm as at idle you almost for sure don't have an air leak. Or: you do but it's intermittent and your data hasn't captured it.
The freeze frame data can be very helpful (or useless LOL), especially if it happens to be rather similar each time.
-ve LTFTs can be quite a few things (such as misreporting MAF or wrong fuel pressure/sensor or even dribbling injectors). Together with lean codes? hmm, not sure.
Misfires are detected by seeing tiny variations that shouldn't be there in the crankshaft signal CKP. That's why the PCM has to learn what a good CKP looks like as part of the drive cycle - done by coast-downs i.e. slowing from about 50mph without braking.
Any form of excess O2 will make LTFT positive (i.e. adding fuel to compensate for the excess O2).
If the LTFT stays about the same at 2500rpm as at idle you almost for sure don't have an air leak. Or: you do but it's intermittent and your data hasn't captured it.
The freeze frame data can be very helpful (or useless LOL), especially if it happens to be rather similar each time.
-ve LTFTs can be quite a few things (such as misreporting MAF or wrong fuel pressure/sensor or even dribbling injectors). Together with lean codes? hmm, not sure.
aholbro1, he's right, you're catching on now. To really figure things out you have to get a handle on what the system is telling you, and why. As deeply as you seem to want to delve into your car's operation, I think it's probably time to consider something a little better and more useful than a Smart Phone and Torque. That's great for a quick look at readings, but to follow, track and log data you need something better.
On that point, what you need now is a way to see what your fuel trims are doing thru-out the load range. That is where you can figure out likely possibilities for the wayward trims. Let me show you and example. Attached are two screens of data logged before and after a purge valve repair. The two data maps at the top are showing the long term fuel trims for both banks, bank one on the left, and bank two on the right. The columns in each map are RPM in thousands, and the rows are load range in percent [the PID is "Calculated Load Value"]. I should note here that in this example the car arrived with a Check Engine light complaint and a P0441 Evap Leak Fault; a failed or loose gas cap can cause that fault, didn't you say you replaced your gas cap?? Look at the trim values in the 'stuck open' picture. High at all low RPM ranges, and at the high RPM/Load combined ranges. But at lower RPM/Load combined ranges they are actually negative or neutral. That told me where the trims were off and gave me a hint. I know this is long winded, but bear with me. I know the purge system uses the engine vacuum to suck fuel vapors off the tank and burn them through the engine. When the purge is open it is basically a purposeful vacuum leak that carries some fuel vapor with it. So that's a good bit of air, with just a little bit of fuel vapor. All that is accounted for in the fueling program. So this purge valve was stuck open, that meant at idle the engine had an air leak that had a little fuel in it. More air than fuel, so the trim went positive to compensate. Now lets consider the HIGHER RPM and LOW LOAD numbers. Those are basically deceleration conditions, right?? That's when the ECM is shutting off fuel, for all intents and purposes. Negative trims at this point mean excess fuel...........low and behold that fuel is vapor coming through the stuck open purge valve at closed throttle! Like I said, long winded I know, but you can see now why just a snapshot at idle or 2500 RPM may not tell you enough to peg the true cause. That is especially true if you might have more than one issue, say a misreporting MAF sensor too, yes?? Now, the 'repair' picture, taken to confirm the repair, shows you what we want to see, everything bouncing back and forth across zero.
Hopefully you see what I'm getting at. Once you determine where things are off program, you have a chance to consider what might cause the problem.
I guess you could say that's a plan, as John referred to.
Good luck!
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aholbro1 (05-18-2011)
#38
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aholbro1 (05-18-2011)
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aholbro1 (05-18-2011)
#40
THanks again. New info since our PM's this morning: "Birthday Boy" re-sprained his previously-broken ankle so the Saturday 6 Flags trip is touch-n-go at this point....I may be loafing around the house Saturday after all and from Steve's post, there may well be some stuff to learn despite the absence of codes. I'll keep in touch...again....humbled by your generous offer. Do get in touch with Motorcarman regarding WDS.
Thanks for assuming such high-minded motives on my part...but I'm actually just trying to quiet the squeak emanating from the steering wheel actuator.... (yes.. I know about the magic elixir for $12 and that's not what I'm talking about....think, think, think...and "I never uttered such a statement!")
Agreed...and my "Fleet" would seem to justify such an expense, and I was close a few days ago when my dsl Excursion was cutting out with no indications as to why, but a thorough search of the Powerstroke forum revealed several instances of the seemingly same intermittent problem occuring to guys' who had AE w/Ford bundle and it wasn't exposing the source - so I held off wondering if maybe the $$ not better spent replacing all the sensors with a history of not making 200k mi and having the capability to shut it down, then discovered the culprit was my Smart phone and Torque
Still intrigued by AE and its capabilities.....but.....the VDP is in need of new Michelin's and everything is running and currently code-free.
Well...I tried! Not interchangeable between 05 and 03 and both the one I ordered from Rock for the 03 and the one I ordered from Amazon for the 05.....fit the 03. (and my pickup, also an 03 but not a Jag, obviously) Wanted to do that b/c having identified no vacuum leak via the spray test...seemed like the easiest "fix" of the known possible causes....I always opt for the path of least work if it is also low-cost!
Good example and great explanation.
Thanks for keeping it stirred, John. John/Steve, curious, is the data from a drive-cycle? or does AE have a routine that runs it through those rpm ranges? (Still wondering how it varies eng. load if that is the case, though)
Still intrigued by AE and its capabilities.....but.....the VDP is in need of new Michelin's and everything is running and currently code-free.
Good example and great explanation.
Thanks for keeping it stirred, John. John/Steve, curious, is the data from a drive-cycle? or does AE have a routine that runs it through those rpm ranges? (Still wondering how it varies eng. load if that is the case, though)