running on lpg...after exiting torque...
truck runs smooth...with good power...

 

We all have to congratulate you. You have graduated with Doctorate and Honors from the Torque Pro diagnostics academy. Soon you will be adding custom PIDs and new gauges for diagnosing all sorts of things on your truck. Torque is fun.


I have reviewed all prior posts looking for additional, or missed, clues - because current readings do not directly explain the reported symptom (Lean -P0174, / misfire(s) on Petrol - smooths out on LPG). I am not overly excited about the high LTFT1 on Petrol. Fuel trim tables are multi-dimensional tables (similar to a rubics cube) with trim readings stored based on several factors such as RPM, MAF, engine Load and so forth. The PCM 'adds' LTFT and STFT together to get an adjustment factor to apply to its factory specified 'BASE' injector pulse width for the 'current' set of conditions. Positive short term trim readings propagate into long term trims based on an exponentially weighted moving average. This is same if STFT is negative, it will PULL LTFT down over time - striving to make STFT at or near Zero.


While I have NO KNOWLEDGE - whether or not the LPG conversion vendor modifies this part of the PCM functionality, but something tells me (when I try to design the system in my 'little pea brain') tells me 'NOT'. I believe the PCM's fuel trim table is the same one on both LPG AND Petrol. NOW, this type operation WOULD present a "SHOCK" to the PCM upon switch over from Petrol > LPG, or visa versa. UNLESS the fuel delivery injectors for both products were _PERFECTLY_ calibrated to deliver the exact identical amount of BTUs in fuel/energy.


Analysis of the Torque readings suggests LPG may be delivering MORE (fuel/energy or BTUs) and the PCM is compensating by reducing LPG injector pulse width(s) - and this is propagating into fuel trims (negative). This 'theory' is quasi confirmed by something you said in post #35 - "but when I switched to LPG the O2 sensor shot up and got stuck at .85ish...fuel trim on bank 1 went to Minus 20%". I am wondering if the reverse happens when you switch to Petrol (after running on LPG for a while since 99% of the time you run on LPG). If the fuel trim tables are saturated with negative going adjustment readings to accommodate LPG ('fuel rail pressure / injector calibration'), and you switch to Petrol which ('fuel rail pressure / injector calibration') requires more fuel - you would see an immediate reaction toward 'more fuel delivery' (lean condition - reaction). Actually - this condition would in fact work itself out with time (though richness of fuel/air mixture could result in misfires until fuel trims settle out to normal. Spec states LTFT >+25% -AND- STFT >+10% will set Lean DTC. Actually the screenshot in post # 40 is still shy of that - so would not set a DTC and might work itself out if driven on Petrol some distance.


OR - we might Try a Battery Disconnect PCM reset, start up on Petrol and perform a Battery Disconnect Relearn Process, then take Torque Readings. Than could 'debunk' this theory.


OR - do you know if there is a provision to 'Adjust' the LPG pressure 'downward' slightly in its delivery system? It seems that would tend to balance the two out. Your Petrol fuel rail pressure seems perfect. About identical to what my 2004 5.4L runs.

 

well...after reseting PCM i drove about 8miles with one stop at comunal centre and no engine light, still no power and shuder in OD.
Fuel trims were ok all thi time when i was looking, bank 1 shot up to 32 just for a moment...
pic 1. 'adapter faulty mesage appeared just second before i took screenshot'

then i exited torque and got this data after some idle(with shake) and reving up to 5000rpm with no miss...great nascar sound ....
6.2mpg on computer...

 

Since you have disconnected battery and cleared PCM, the next time you get check engine light please grab Freeze Frame data - BEFORE clearing DTCs. /// From Torque opening screen select >Fault Codes, >Menu Button, > Freeze Frame, then share it or email it to yourself ///


Also, a Mode 06 test report would be interesting to look at. ///From Torque opening screen select >Test Results - give it plenty of time to complete the tests (maybe 3 minutes as the screen grows longer), then >send as above.
I'm working on a theory. (Heaven help us!).


And WHERE did all the smart guys go? You going to sit on the side line and watch me embarrass myself - all by myself?


EDIT:
Other than occasional misfires (apparently only on Bank1), what could cause Long Term Fuel trim to be exceptionally high while STFT is relatively normal??

 

will do all that...thanks
and no emmbarrasment here...you helping me a lot!
sometimes im thinking of selling truck on bad days but after all and when(not if) we fix it I will be fully qualified 3v triton mechanic and it would be shame to let it go

 

ok on the way home from work i got weird data...fuel trim over +40%....and saw O2 bank1 stuck at 0.9 for about 5second but not much increase in fuel trim graph after that....
no engine check light and not able to get any test results...could this be bad/low quality OBD reader? paid only about $7 for mine...

 

This over our heads for sure , Kudos for your efforts to resolve this. I don't think too many are brave enough to try it .
I can only say you are giving your Brain a good work out . And that's good . Can't really follow but we watch .

 

Awe come on @redfishtd, jump in here. That LTFT1 being so positive ---- with STFT1 being relatively normal..... "STINKS" of random intermittent misfires. Misfires will slam fuel trim positive because the cylinder exhales a BUNCH of unburned oxygen - and O2 sensors, being the "DUMB" device that they are (O2's do not sense fuel richness or lean-ness, only 'OXYGEN'). So the O2 would sense TOO MUCH OXYGEN & slam STFT MAX as the OP reported in his latest post. That "+" STFT propagates to LTFT very quickly, (as we see in the screenshot of 24.2 %), Then if misfires cease - STFT returns to normal but it takes a little time for LTFt to return to normal. ????? This is theorizing on my part - come on help me out here. What do you think?


With the KNOWN propensity for 5.4l 3v Tritons to have misfire problems span plug changes (The OP reports changing plugs), is it possible this is a case where carbon build up in the heads has damaged the NEW plugs, or unclean workmanship, or failure to replace boots / use dielectric grease did not FIX misfires???? And @LudoUK is simply the victim of a poorly executed spark plug job???




EDIT: Does not exactly explain why the truck seems to run fine on LPG. But I note that LPG has a typical octane rating much better than Petrol. PER Wikapedia:
80% Propane, 20% Propylene 93.5
50% Propane, 2% Ethane, 48% Propylenea 89.7
95% Propane, 5% n-Butane 96.0
The typical 5.4L 'shudder' is under light load / 45-50 mph, a point where VCT is max advance and NOT moderating the 'relatively high' (9.8:1) compression ration of the 5.4. Perhaps LPG is less suseptible to light load misfires. A definate unknown here for me???

 

???? Have you ever had a 'flashing CEL'?

Your 'weird data' sounds like another spurt of misfires --- and it connects one more dot in development of my theory. I would still like to see Mode 06 data - and I can think of NO good reason why you can't get Test Results. A 'Flakey' Bluetooth adapter is the only reason I can think of you can't get test results. You should be able to run Mode 06 tests ANYTIME. (If some dependent tests are not ready - it should report THAT). I have never liked the "Adapter Error" you've been getting. And - having a cheap adapter myself - I have no good recommendations.

It would be most helpful to know if intermittent misfires are responsible for the elevated LTFT1. Mode 06 (Test Results) should tell us number of misfires in the current drive cycle AND the cumulative count BY cylinder for the last 10 drive cycles. Similar live data is available on our trucks - but requires creating several Custom PIDs. You ready to learn how to do that? It shows the full breadth of the Power of Torque.

The PCM captures a considerable amount of OBD data about misfires. The custom PIDs each have to be entered into and defined to Torque separately. Then when you go to the add a gauge routine, these PIDs show up in the scroll list. After inputting the PIDs, you can create a separate dashboard with some digital gauges and On/Off dials for Monitoring Misfires. Here is the dashboard I've set up for Misfire monitoring.






Misfire Monitor Torque Pro dashboard

If you (or any of the Torque Pro users that happen to be following us) care to replicate any part of it, here are the custom FORD PIDs (for the 5.4L Triton) with discriptions and formulas.

I prefer to always place an underscore character in front of my custom PID names. This keeps them separate from Torque's PID list - and makes them sort to the front (selfish me). Header for all these PIDS is "Auto" (or usually you can leave them blank). None require a Start/Stop Diagnostic command.

-------------


Continuous Code Counter (fault & pending)
Mode/PID: 220200
Long Name: _Continuous Code Counter
Short Name: DTC_CNT
Min/Max: 0, 255
Unit: Cnt
Formula: A


Total number of On-Demand Codes
Mode/PID: 220202
Long Name: _Total Number of On-Demand Codes
Short Name: DTC_CNTD
Min/Max: 0, 255
Formula: A


Number of Drive Cycles - SINCE the last Misfire. (This Counter increments ONCE - for each Drive Cycle and is RESET when DTC's are CLEARED and when a Misfire is detected AFTER the first 1000 Engine Revolutions). Misfires during the first 1000 Revs do NOT reset this counter.
Mode/PID: 2216DC
Long Name: _Number Drive cycles Since DTC CLR or MISFIRE
Short Name: MFF_0_CNT
Min/Max: 0, 65535
Unit: Cnt
Formula: A*256+B


Total number of Misfires (during the curent drive cycle. Includes misfires occurring during the 1st 1000 Revs.)
Mode/PID 221616
Long Name: _Total Number of Misfires
Short Name: MFTOT
Min/Max: 0, 65535
Unit: Cnt
Formula: A*256+B


MISFIRE OCCURING. Flag is set if vehicle exceeds limit of misfires during first 1000 revolutions or any four 1000 rev blocks during the drive cycle.
Mode/PID: 221102
Long Name: _Misfire Occurring Flag
Short Name: Misfiring
Min/Max: 0, 1
Unit Yes/No
Formula: {A:7}


Engine RPM at time of lastest Misfire. (captured for Freeze Frame Data)
Mode/PID 2216D3
Long Name: _Engine RPM at time of Misfire
Short Name: MFF_RPM
Min/Max: 0, 6500
Unit: RPM
Formula (A*256+B)/10


Engine Load at time of latest Misfire. (Captured for Freeze Frame Data)
Mode/PID 2216D4
Long Name: _Engine Load at time of Misfire
Short Name: MFF_LOAD
Min/Max: 0, 100
Unit: %
Formula (A*256+B)*(128/32768)


Vehicle Speed at time of latest Misfire. (Captured for Freeze Frame Data)
Mode/PID: 2216D5
Long Name: _Vehicle Speed at time of Misfire
Short Name: MFF_VS
Min/Max: 0, 120
Unit: MPH
Formua: A


Intake Air Temp at time of Misfire. (Captured for Freeze Frame Data)
Mode/PID: 2216D6
Long Name: _Intake Air Temp at time of Misfire
Short Name: MFF_IAT
Min/Max: 0, 200
Unit: Deg. F.
Formula: (A*9/5)+32


Engine-Off SOAK at time of Misfire. (Captured for Freeze Frame Data)
Mode/PID: 2216D7
Long Name: _Engine-Off SOAK time at time of Misfire
Short Name: MFF_SOAK
Min/Max: 0, 1000
Unit: Minutes
Formula: (A*256+B)/60


Engine Run time at time of Misfire. (Captured for Freeze Frame Data)
Mode/PID: 2216D8
Long Name: _Engine Run Time at time of Misfire
Short Name: MFF_RNTM
Min/Max: 0, 255
Unit: Minutes
Formula: A/60


Throttle Position at time of Misfire. (Captured for Freeze Frame Data)
Mode/PID: 2216DA
Long Name: _Throttle Position at time of Misfire
Short Name: MFF_TP
Min/Max: 0, 5
Unit: Volts
Formula: ((A*256+B)/32768)*5


In Drive at time of Misfire. (Captured for Freeze Frame Data)
Mode/Pid: 2216DD
Long Name: _In Drive at time of Misfire
short Name; MFF_PNP
Min/Max: 0, 1
Unit: Yes/No
Formula: {A:1}


Misfire Wheel Profile Learned in KAM (Misfire monitor correction profile for irregularities in CKS tone ring learned)
Mode/Pid: 2216DD
Long Name: _Misfire Wheel Profile Learned in KAM
Short Name: MPLRN
Min/Max: 0, 1
Unit: Yes/No
Formula: {A:0}


Misfire Monitor completed this Drive Cycle - element of comprehensive continuous OBDII Monitors (Must complete in order for certain other Monitors -ie: Catalyst Monitor - to run)
Mode/PID: 22095D
Long Name: _Misfire Monitor Status
Short Name: MISSTAT
Min/Max: 0, 1
Unit: Yes/No
Formula {B:7}


Fuel Status Monitor completed this Drive Cycle - element of comprehensive continuous OBDII Monitors
Mode/PID: 22095D
Long Name: _Fuel Status Monitor
Short Name: FUELSTAT
Min/Max: 0, 1
Unit: Yes/No
Formula: {B:4}


Happy Torqueing

 

wow...thanks for all again! You are giving me a lot of your time!
I have tried 99octane petrol and no change
I started today swaping COPs, have got only one spare now, original owner said they had problems with COPs sometimes in 2014(25k miles ish ago) but i dont know if they replaced all of them. All were motorcraft with like new boots. I replaced one since when i got missfire #3 code. Only COPs i can get here are 'Standard product', was looking at ebay but not sure if sellers selling new motorcraft cops in states are trustworthy. One replied COPs are not packed in bags...its what pulled me of. And dont realy want to pay $80 for one COP. Swaped nr.6(easiest ) and no change. Will continue tomorrow with bank1.
I was getting flashing check light when on petrol, since i replaced all spark plugs no flashing engine light, only P1071 what i believe now is related to something with lpg.
All spark plugs were the same colour(done no more than 100miles after missing/shake/shudder started). No much of carbon, see picture, i replaced them by myself but must admit i did not put any grease to COP springs as i have none atm.
'test incomplete or failed' is only what i see when opening torque test results....

maybe not related but my problem started after truck stood 4weeks in wet december, run ok first day on the way to work, on return i was testing it on petrol only and after about 2minutes of pushing it harder up the hill problem started....must say that some days it does not run perfect on lpg either...