Any thoughts, comments and questions people have on this are wholly welcome ...

Had an error on the car reporting the MAF sensor not working. Ended up disconnecting it until the new one arrived. New one fitted, and even still, the car isn't really running right. I've reset the adaption values, but after a short drive, it begins to stumble and falter on pick up, then it'll pull like a train.

So I did a run with the diagnostic on it recording some ( not all ) of the engine data.

At first I thought the MAF may be faulty, but versus throttle position ... it gives what appear to be good readings ... only thing I'm wondering about is the high values of them ... idle is about 35 to 40kg/hr and about 1000kg/hr peak ??? Is that right for a 4.4? Here is the throttle and MAF readings

Click image to enlarge

Quote:

O2 Control Bank 1-2:This shows lambda control status of cylinder bank 1/2. The value should nominally be 1 but typically will vary either side of 1 as part of the lambda control.

I dont know how it calculates it, but when you plot it against the same run, you get this:

Click image to enlarge

Does that look right to people?
At 100% throttle, its bang on 1.
When under medium load, it wavers about.
Why does it drop to 0.74 on idle ? Is that right? I would have assumed at idle, based on the help file, that it would try to achieve a value of 1 all the time.

Also ... at about the 111 point when I slowed right down and accelerated away. It stumbled hard at that point when i blipped the throttle moderately hard and continued to stumble when I pulled away the following times. Prior to that point I would have said it was running reasonably smoothly. With that in mind ... it looks like the lambda readings before that 111 point are averaging lower than after the 111 point.

Lastly, just cause, here is a graph of throttle, speed and rpm ...

Click image to enlarge

 V8 or else ...

Fisha,

Did you get a OE meter or a copy, the reason I ask is that I bought a non genuine one and it was SH :censored:TE.
Made it do exactly what yours does. No matter what I did on Autologic it was having non of it.

Jonno 5.0 supercharged autobiography
Gone-4.4 Vogue Lpg now unmapped
4.6 HSET Turbo Lpg mapped
Gone-Defender 90 200tdi
Gone - 3.9 Sprintex supercharged LPG
Gone - 3.9 Vogue LPG

I went with a bearmach one... Figured it would be better than a britpart one. Maybe not eh?

.... Beginning to wonder though. If its telling the engine more air is getting in than reality, then the engine will add more fuel than needed ... Possibly making it run rich.

But surely the O2 sensors would counter that ?

I'd like to know what other people's kg/hr at idle and at load are to compare against ,y new one. V8 or else ...

Can check that on Saturday if it helps 5.0 supercharged autobiography
Gone-4.4 Vogue Lpg now unmapped
4.6 HSET Turbo Lpg mapped
Gone-Defender 90 200tdi
Gone - 3.9 Sprintex supercharged LPG
Gone - 3.9 Vogue LPG

Jonno, if you could that would be great.

Been messing with the car again, seem to be now I'm regularly getting running rich errors .. Will post the error up shortly.

Going back to the O2 graph, in general , does rich running equal less than 1 readings ? V8 or else ...

This is information from my 2000 4.6L RR.
I've never looked at the 2005 FFRR 4.4L.

I think mine display pounds/minute.
At idle, mine was always right around 1, sometimes a little less.
60lb/hr or about 27kg/hr.

My O2 sensors bounce up and down; this is normal.
They show rich for a moment, the computer leans out the mix.
Then they show lean, computer richens it up.
back and forth, back and forth.
Since the O2 sensors are different on the 2000 vs. the 2005, actual voltage numbers don't compare.
The 2000 O2 sensors vary between 0.8V high and 0.1V low.
Theoretical perfect is right around 0.45V.

How is it possible to have > 100% throttle? Afterburner? Jim
2000 NAS HSE
2005 NAS HSE

I had similar symptoms to yours and the fault showed up as a MAF sensor a previous garage had changed all 4 of my lambda sensors because of emissions readings but I still had the issue. I then saw Andy White at whites auto services in edinburgh and had the MAF changed and the fault was still there, the guys at whites then stripped out the throttle body and hoses and cleaned the internals and linkages, they said that there was a bit of gumming on the flap inside, since this was cleaned I've not had any problems.

125% throttle is kick down I think.

Looking through other readings, it shows my calculated air leakage as being 11kg/hr ... That seems massive ... I'll clean things up and continue for leaks.

As mentioned before: This is an error I am regularly getting:

Quote:

THE ENGINE MANAGEMENT FAULT CODE MEMORY CONTAINS CODES FOR THE FOLLOWING FAULTS -:


--------------------------------------------------------------------------------
FAULT 1


P0172 - SYSTEM TOO RICH BANK 1.

THE FAULT STATUS DATA FOR THIS FAULT IS -:
DETECTION CYCLE COMPLETE.
THIS FAULT CAN BE READ WITH A GENERIC OBDII SCAN TOOL.


THE FREEZE FRAME DATA FOR THIS FAULT IS IS -:
LAMBDA CONTROL STATUS BANK 1 = 2.
LAMBDA CONTROL STATUS BANK 2 = 2.
RELATIVE LOAD = 3.906.
ENGINE TEMPERATURE = 104.
CONTROL FACTOR BANK 1 = .7956.
ADAPTION FACTOR BANK 1 = .741.
CONTROL FACTOR BANK 2 = .7722.
ADAPTION FACTOR BANK 2 = .741.
ENGINE SPEED = 1160.
VEHICLE SPEED = 42.


THE DATA STORED THE FIRST TIME THIS FAULT OCCURED IS -:
APPROXIMATE ODOMETER VALUE (KM) = 171210.
ENGINE SPEED = 1160
INTAKE AIR TEMPERATURE = -24.
THROTTLE ANGLE = 42.0082.
INTAKE AIR FLOW A to D VOLTAGE = 41.25

--------------------------------------------------------------------------------
FAULT 2


P0175 - SYSTEM TOO RICH BANK 2.

THE FAULT STATUS DATA FOR THIS FAULT IS -:
DETECTION CYCLE COMPLETE.
THIS FAULT CAN BE READ WITH A GENERIC OBDII SCAN TOOL.


THE FREEZE FRAME DATA FOR THIS FAULT IS IS -:
LAMBDA CONTROL STATUS BANK 1 = 2.
LAMBDA CONTROL STATUS BANK 2 = 2.
RELATIVE LOAD = 3.906.
ENGINE TEMPERATURE = 104.
CONTROL FACTOR BANK 1 = .7956.
ADAPTION FACTOR BANK 1 = .741.
CONTROL FACTOR BANK 2 = .7722.
ADAPTION FACTOR BANK 2 = .741.
ENGINE SPEED = 1160.
VEHICLE SPEED = 42.


THE DATA STORED THE FIRST TIME THIS FAULT OCCURED IS -:
APPROXIMATE ODOMETER VALUE (KM) = 171210.
ENGINE SPEED = 1160
INTAKE AIR TEMPERATURE = -24.
THROTTLE ANGLE = 42.0082.
INTAKE AIR FLOW A to D VOLTAGE = 41.25
VEHICLE INFORMATION

While you're under the hood staring at the engine, trying to make your wife think you know what you're doing...

Spray some throttle body cleaner on all the vacuum lines & air hoses.
If 1 of them is cracked, it could allow unmetered air into the system.
The TB cleaner is VERY flammable, and you'll hear the idle increase.
I found a vacuum leak that way.
Don't smoke while you're doing it.

Both banks rich?
IIRC, a vacuum leak will cause both banks lean, and the computer gooses the fuel mix to compensate. Jim
2000 NAS HSE
2005 NAS HSE

Just checked with Autologic and my idle runs at about 25kg/hr.

Maybe one of your your lambdas is getting lazy?
That was how I solved mine.

Jonno 5.0 supercharged autobiography
Gone-4.4 Vogue Lpg now unmapped
4.6 HSET Turbo Lpg mapped
Gone-Defender 90 200tdi
Gone - 3.9 Sprintex supercharged LPG
Gone - 3.9 Vogue LPG

I've tried spraying the whole area with wd40 .... No changes. Tried opening the oil filler and dipstick... No change.

My maf seems to reading high ... Which would explain that if the engine is being told that more is gng in than actually is, then it'll be throwIng more petrol in than is needed ... Leading to the rich running.

I did a long run which was data logged , I've still to churn the data, but at a glance, once the engine showed a fault and running rich, it defaulted to a setup that seemed to ouch the lambda values back up around 1 all the time.

Will churn the data soon and post any findings. Now thinking that I should have spent the extra money and got a genuine maf. V8 or else ...

Okay doky ...

Still be tinkering away at this ... algt2 was on the money I think. Bought a bottle of brake cleaner and doused the throttle body and butterfly with it and cleaned it all up. There was a bit of soot and dirt around all the edges.

Had to have the ignition on and bricks on the pedal to hold the throttle butterfly open .. if you unclipped the connector plug to the unit even when fully open, the flap would spring shut.

After doing that, reset everything and made the car re-learn the throttle.

Started it up, it flicked over to gas quickly cause the engine was still warm:

Air intake = 22 - 25 kg/hr ... result ... definite difference and about the correct value.
O2 readings = 0.74 as before ... bummer.

Reset everything again ... started it up and forced it to stay on petrol.

Air intake = correct
O2 readings = 1.00 .... woohooo!

Sooo, i think during all the time the MAF was failing, the LPG was over compensating somehow and has learned a really duff set of values.

I also think that the throttle body was dirty and preventing the butterfly flap from fully closing. This was holding it open ever so slightly, causing my high air intake readings when at idle ... and probably goosing up the associated fuel mix too.

I'm going to run the car on petrol for a few days to let the petrol ECU settle down to its correct values and see if the lambda readings stay at 1. If thats all good, then i'll get the LPG kit tuned back into line.  V8 or else ...

Fingers crossed, had mine cleaned up about a month ago and touch wood it's been great, before that I got reduced performance warnings about three or four times a day along with rough idle and stalling!

I even think visibly there was a differenc ebefore and after the cleaning. The flap looks like it closes further and tighter now.

I also watched it do it's relearn routine and afterwards it definitely moved to different positions. V8 or else ...

bad news ... its still reporting running rich. its doing my head in.

I dont have time to around with this anymore. its easily been the most unreliable car i've ever had.

stroll on a defender at this rate. V8 or else ...