Instructions to change fuel maps on 14CUX Griffith, Chimaera

[stevesprint]

Donkercam said:

Hi
It's mild shacking, I want to conserve the cat.
Thanks
Cam

Sounds like it might be worth checking your vaccum advance, the diaphragms do perish after 20 years
https://www.pistonheads.com/gassing/topic.asp?h=0&...

[stevesprint]

indigochim said:

I have a 450 if I was to run an aftermarket set of manifolds with no cats at all would the "TVR Griffith 430 Precat & TVR Chimmaera 450 CAT combined in Land Rover final revision R3652" be the right code to stick on a chip?

I bought a writer and some chips some time back I fancy giving it a go.

"TVR Griffith 430 Precat & TVR Chimmaera 450 CAT combined in Land Rover final revision R3652" contains the following so you can switch between the two maps

map 2 (Green non cat) is the factory 430 & 430BV Precat map
map 5 (White CAT) is the factory 450 CAT map that you are probably currently running but with later program code

Interestingly, the 430BV Precat map is richer than the 450 cat map and this 430BV Precat map runs ok in my 4.5 so might be ok in your 450 (4.6) but you should really get it checked on a rolling road.

Please let me know if you experience any issues with that combine tune especially with idle as we’ve learnt a lot since then and its probably time to update that tune.

[stevesprint]

davep said:

Maybe the injector firing/inlet valve open for half a squirt scenario occurs but twice per engine cycle, but this depends very much on what else the ECU is doing:

Fuel stagnating in the inlet tract and on the inlet valve isn't going to be a problem, or is it?

Check out that big pressure pulse that occurs as a result of the valve closing.

Dave

To be clear we know the "injector firing/inlet valve open for half a squirt" twice per crank revolution therefore one per cam revolution.

Also don't forget the mechanical advance (upto +18°) and vacuum advance (upto +10°) will also alter the injector firing time up to 28°, I always assumed that's why the code smooths the rpm.

Are the pressure pulses the vacuum in the inlet?

[stevesprint]

Donkercam said:

Hi Steve,

Is your "TVR 430 Precat and 450 CAT based on LR R3652 with Extended Fuel Table to 6250RPM" program run on chimaera CAT 500 ?

Thanks

Cam

Cam
No sorry not to my knowledge, however I could build a 500 version but you'd have to get it checked on a rolling road.


Here's the factory 1994 Griff 500 map and below is the factory Chimmy 450 fuel table stretched to 6250 rpm which surprisingly have a higher fuel multiplier from the factory, meaning richer.

[stevesprint]

davep said:

Five years ago ...

Dave
Thanks for the picture and blast around the Alpine test track & down the mile straight, you were so fast and smooth no one would know you drive with a hand control. I was also very impressed with your clever clutch switch on your gear lever, its like a manually controlled BMW SMG gearbox.

You can tell it was a fab day by the size of the smile on your face.


Lets hope Millbrook is repeated again next year as it was cancelled this year.
Stay Safe, Steve Sprint

[stevesprint]

indigochim said:

Finally put this in the car. I was hoping to fit a zif socket while I did the swap but as it happens there's no space for one. I hung of on fitting as I didn't fancy a major change before taking the car to Europe but now I'm back have bitten the bullit. I'm in quarantine till tomorrow so didn't take it for a run but will be out in it on Sunday for a trial. I'm also planning on fitting the 4 port Bosch fuel injectors soo too. Maybe after that I'll have to take a trip to Chesterfield for a remap or a swap to an aftermarket kit.

As it is on the drive it ticks over and revs nicely.

Guess I was lucky & found a zif socket that fits, Joolz should have no trouble remapping your 14CUX for 4 port injectors.

[stevesprint]

TRIUMPHBULLET said:

Hi all, I had a play in the car last weekend and found that the engine would cut out at almost 4000 rev/min, it is really smooth up to this point. The boost level shown at the time was 5lb/in2. Normally aspirated the car only reached the last but one bottom row even at 5000 + rev/min. the engine is a std 3.9, std cam and I have put Steve Sprints TVR 4.3 precat map in for now.
Had a look at the log and fuel map seems to hit the bottom row just before this. My passenger confirmed this as they were looking at the Rovergauge display.
If I want to extend the afm range of the map do I increase the Row scalar value (91 at moment) or decrease it to compensate. Also, will altering the Maf scalar offset value up (30 at moment), move the idle highlight up the table or down? I suspect even a modest alteration will affect the table so wish to tread carefully.
I know the fueling will need altering but that seems pointless till the afm scaling is correct.
Regards, Paul.

On full load you want the active row between 6.5 & 6.8 in the log files.

Increasing the AFM scalar pushes the active row downwards on the screen, (increasing currentFuelMapRow in the log).

Increasing the AFM Row Offset (at prom location 1C8) decrease the active row.

You’re right the slightest change to the row scalar does make a big difference to the AFR, because you’ll suddenly start using richer/leaner cells.

When your engine cuts out at 4,000 rpm are you getting any fault codes like 19. Throttle Pot to low and MAF to high? as I know that fault causes the engine to cut out at 4,000rpm. If its that fault code, what prom revision are you run as Land Rover desensitizes that fault code in the later revsions.

I suspect Mark is right and you are maxing out the 5AM too early and therefore I would recommend the Bosch 4.6 MAF, its bigger, more reliable and still availble new but would require a full remap unlike the 20AM.

[stevesprint]

KiwiRRC said:

Hi All,

I have managed to get my hands on a 2nd 14CUX to have more of a go with and I love how easy it is to swap in and out so have a few more questions.
1) It turns out I should have been using low compression R3362 and my RRC does have Cats!. Is there a file available for that for download.
2) A mate is looking to put a 4.6l V8 in his RRC running off a 14CUX. Is there a recommended tune for that?
3) Finally - if I really what to play - is there one of your racing tuning that pep up a 3.9l low compression V8? Or is that just silly?

Cheers
Dave

Dave,

Sorry for the delayed reply and sorry I don’t have R3362, I’ve got R3360, R3361 and R3365 but not R3362, the Aussie map above was 3.5L.

I don’t have any low compression tunes and would be interesting to see the differences, do you have any? Maybe you should try R3652 http://www.remap-14cux.uk/bins/LR_R3652_3.9_HighCR... .

I’m not sure if you realise TVR Chimaera 450 are in fact 4.6 with 4L pistons to raise the C/R so your friend could use the standard TVR 450 map to get him up and running.

[stevesprint]

Bmanetd said:

I've got 2 projects in the works right now. One is a 4.2L and the other is a 4.6L and both owners want to run 14cux systems with O2 sensors. Would your "TVR 430 Precat and 450 CAT based on LR R3652 with Extended Fuel Table to 6250RPM" prom be adequate for them? I'm assuming different tune resistors for the 430 and 450 maps?

Thanks!

Hi Bmanetd

For the 4.2 with CAT's I would suggest they run map 5 (white) with LR OEM http://www.remap-14cux.uk/bins/LR_R3384_4.2_1995_U...

4.6 with CATs they should also use map 5 (White) but try http://www.remap-14cux.uk/bins/TVR_R2967_450.bin as TVR 450 are in fact 4.6.

Good Luck and let us know how it goes.

Steve

[stevesprint]

Bmanetd

You shouldn’t really need multiple maps as explained by Blitz but if required I would suggest replacing the 14CUX tune resistor with a rotary switch with soldered on resistors for each map, works a treat for me. You don’t need a Moates 2Timer.

Speaking from my experience, you can successfully change 14CUX tunes with the ignition off or the ignition on but not running and does NOT throw a tune resistor fault code. You can not change tunes while running which throws the tune resistor error on some proms, but not all, and stays on the current map, it does not switch to map 0 on any prom.

Map 0 is the default map selected without a tune resistor and not a limp home map, for example if a temp sensor dies the ECU uses a default value and stays on the current map. I can assure you a Precat does not switch to the CAT Map 0 when the AFM dies but instead the code estimates engine load from engine speed and throttle position.

I’ve had my Moates Ostrich permanently connected for the last 5 years and never missed a beat, I’ve even used it on a track day as I forget its there, however it is carefully secured behind the battery so it doesn't move around.

Dave, love the picture especially Mercedes on the typewriter, very funny!!

[stevesprint]

Issac
How’s your supercharged Triumph TR7 Bullet?

Here’s a link to my latest TunerPro definition file dated 22/03/2020
http://www.remap-14cux.uk/TunerPro/TunerPro14CUXCo...
Please let me know if you need anything adding or fixing and I’ll do my best.

If you mean the one table ‘accelPumpTable’ in the data.asm then sorry no, however

I have got my head around the six row ‘throttle pot direction & rate’ tables in each map which are called in TunerPro “Map (1-5) THROTTLE TABLE”.

1st Row Temperature (hot to cold, left to right) only one column comes into play at a time
2nd Row Throttle Opening Max throttle fuel added
3rd Row Throttle Closing Max throttle fuel subtracted
4th Row Throttle Open Multiplier
5th Row Throttle Closing Multiplier
6th Row Throttle Opening extra fuel decay time

Setting the decay time down to 01 the extra throttle fuel does NOT decay below 4000rpm at which point this table is ignored due to the processor running out of time between sparks, therefore reducing row 6 increases the decay time.

This a very important function of the throttle pot which you can see with afr guage when the max is set to 01 the AFR goes very lean for a split second and the engine hesitates when suddenly flooring the throttle. The Bosch AFM I use has a quicker response time so I had to reduce this throttle pot extra fuel, I believe this throttle fuel could be increased to eliminate hesitation with cheap copy 5AM AFMs.

[stevesprint]

Brilliant Work Neil, CG Cobra and Dave plus great to see Dan back on top form, sorry I can’t contribute with the hardware but certainly a helpful & interesting read.

Mark Adams installs the Omex ignition only ECUs with the 14CUX and I assumed he uses the Tachometer output to trigger the 14CUX but I don’t actually know, can anyone confirm. CG Cobra, does your ignition ECU have a Tachometer output?



I'm currently interested in how the introduction of the leaner E10 fuel in the UK in September will effect the running of our 14CUX vehicles. We all know the 14CUX narrowband lambda sensors only reads richer or leaner than stoichiometric but will the stoichiometric point shift with the leaner E10 fuel so the code automatically injects more fuel? Also what about above 3,400rpm & will non-cat cars running open loop need the main scalar increasing or is the difference so negligible it shouldn’t cause any issues?

To get the best of both fuels would non-cat cars require 2 maps? Any excuse to run dual maps.

Also, if I don’t switch to mapping with Lamba how much richer should the following target AFR be for E10 fuel?

11.5 Best Rich Torque at Wide Open Throttle (WOT)
12.0 Fast opening throttle & Accelerating
12.2->12.5 WOT Best safe Power/Acceration 2000-> 4500
12.5->13 WOT Best Performance 3000 -> 6000

13.5 Best non-cat open loop idle
14.7 Stoichimometic least Pollutants
15.5 Lean Cruise but not the very best for the environment
15.5-16.5 Best Economy

[stevesprint]

spitfire4v8 said:

The weakening effect of 10 percent ethanol is less than 3 percent on the mixture strength. Unless you have a car already running on the weak side of safe you won't notice a difference.
Anything under lambda control will automatically richen up.

Thanks for your reply, is that 3% less from the current E5 or gasoline?

I’ve read/heard stoichiometric for E10 is 14.1 oppose to gasoline 14.7, therefore on full load I’ve been aiming for low 12s instead of high 12s & hope the following AFRs will also be ok with E10.


Joolz, you can see I'm running your suggested rpm columns

[stevesprint]

Steve
Might be worth contacting spitfire4v8 (Joolz) as he removes 5AM when installing after market ECUs, I’m sure you know all 5AMs are the same regardless of engine size.

Unfortunately a 3.5 will not flow enough air to use a GEMs 20AM, alternatively to future proof your Rangie you could try the later Bosch 4.0L Land Rover Discovery 2 MAF (AFM) 0 280 217 532 / ERR7171G but would require a step down hose adapter & a full re-map which Joolz could do for you.

I've been running a Bosch MAF 4.6L for the last 3 years and has proved 100% reliable and more consistent with varying engine bay temperatures because the electronics are inside the cool air stream.

[stevesprint]

Thanks for your kind words and interest.

Well done, excellent especially as you’ve found more stepper 180 counts than I did a few years ago for an overseas request but still ran ok with a GEMs plenum.

The stepper is also fully re-opened during shutdown in shutDown.asm line 120 but interestingly it already set to re-open C8 = 200 steps which I increased to DC = 220 but sounds like you don’t need to and is only a precaution.

Good Luck, Steve

[stevesprint]

Discoveryunlimited

Sorry for the delayed reply, I’ve been crazy busy in the garage lifting my Griff body and stripping the chassis for a full blasting, zinc and powered coating.

Maybe you are referring to the coolant temperature multiplier table at C45B or C791, however if your startup is rich I suggest you concentrate on reducing the 12 x 3 cranking fuelling table in the 5 maps.
for example
; 130 102 95 85 56 42 22 7 -2 -10 -14 -16 Coolant Temp in Deg C
DB $00,$12,$1B,$25,$47,$61,$90,$B0,$C8,$DA,$E4,$E8 ; <-- coolant temp sensor reading (low is hot, high is cold)
DB $0B,$0A,$07,$0D,$18,$18,$25,$30,$4E,$59,$6D,$75 ; <-- cranking fueling value above zero deg F (stored in X009B)
DB $1C,$0D,$06,$0A,$10,$12,$14,$1A,$2C,$31,$39,$44 ; <-- time fueling component, 1 Hz countdown (stored in X009C)


You’re right the Bosch MAF does saturates much quicker which is not idea, however I’m sure you’ve read I’ve been successfully using the Bosch MAF for several years now including 3 trackdays and found its output far more consistent with very high engine bay temperatures as its the electronics remain cool inside the intake airflow.


1. What size is your engine? A 4 litre will not max out a MAF with 90mm inlet and therefore will not reach the bottom of the fuel table plus the idle air speed will be too slow to measure accurately. The 0 280 217 532 Disc 2 4L you mention has the same replaceable sensor cartridge as the 0280 218 010 - 4.6L P38 MAF that I’m using and luckily is also used on BMW 5 & 7 series of the same era.


2. According to Dan The MAF behaviour is very difficult to model and based on King's Law for hotwire annemometers using a ‘4th order linearization polynomial equation’ & is a very impressive bit of coding for an ancient 8-bit processor without a math co-processor.

Dan also said
“The AFM readings can be erratic. The 14CUX code seems to deal with this by keeping 2 readings, a high reading and a low reading and averaging or summing them in the code. More modern systems have Helmholtz canisters and I've wondered whether the 14CUX system might benefit from one”. Also the AFM gauze is very important & create a laminar air flow to help reduce the erratic readings.

Dan once suggested a look up table would be more flexible, save MPU clock cycles in the interrupt and less hard to implement but sadly is well beyond my limited programing abilities.

As a result I’m using the Bosch MAF with the same standard MAF maths/programmed equation but leaned off the main fuel table where the MAF voltage saturates quicker and also had to leaned off the throttle acceleration table at C3FB & C731, plus I tweaked the following row/load offset and multiplier

C1C7
- AFM Row Table Offset, shifts the whole table uniformly up/down
- increasing deceases active row
- LR/TVR = $001E Steve Bosch = $0036

C483 Map2 & C7B9 Map5
- Row Scalar/Multipler increases/decreases the usable range of the table
- Increasing uses more rows
- TVR 5AM 4.3L & 500L = $91, Steve Bosch = $EF

With any luck you maybe able to workout the other 3 MAF linearization equation coefficients/tuning parameters at
C1C3
C1C5
C1C9


3. You really don’t need a piggy back voltage converter like an Arduino Nano as I’ve proved we have a good workaround that’s more consistent and reliable but unfortunately does require a full remap.



I personally think it would be really cool to ditch the MAF for a MAP sensor and use the tune resistor input for air temperature input, but sadly that’s also well beyond my very limited programing capabilities.


Please let us know how it goes.
Cheers, Steve

[stevesprint]

100SRV

Welcome & sorry for the delayed reply, I assume you mean your 14CUX not 14CU.

Yes you are correct, cumulative, meaning the Neutral, A/C & Heated Screen idle adjustments are all add/subtract together from the base idle.

The idle speeds are RPMs in hex at the following Prom Offsets

1. Neutral: 159/15A
2. A/C: 15B/15C
3. Base Idle: 176/177
4. Heated Screen: 1E9/1EA

1. I believe the Neutral adjustment lowers the idle in drive, but not 100% sure, can an auto owner confirm.

2. A/C adjustment increases the idle when the A/C is on.

3. The heated screen input is the big surprise as it actually lowers the idle speed just when you need it increased and I believe that’s why its always 00 and never used. However, I’ve also noticed when turning on the heated screen input the idle momentarily increases before it drops by the offset and believe that why my TVR cooling fans +12V are connected to pin 8 for the heated screen.

The 14CUX was designed to be a digital copy of the analogue 4CU with the same feel but I guess Lucas took that literally and also copied all the bad side effects.

Edited by stevesprint on Wednesday 18th January 00:03

[stevesprint]

Sorry I’m late to the party, I’ve been distracted rebuilding my Griff after a full chassis refurb and its finally back on the road.



Adam, Welcome, it's always great to hear from 14CUX owners other side of the world, a picture would be interesting.

I suggest you start again with your Land Rover R2832 3.5 Australia Map1 BIN map as you shouldn't have to change your row scalar from BC. The row scalar controls how far the active cell goes down the main fuel table. On full throttle your active cell should be some where between the bottom 2 rows. Bigger engines flow more air and hit the bottom row easier & therefore have a smaller row scalar. Leave yours at BC unless you're not hitting the bottom row.

In theory, installing bigger injectors you should only need to reduce you main fuel table multiplier & in practise that's correct, however I also had to fine tune a few cells in the main fuel table.

Starting with your R2832 3.5L map reduce your main multipier so you can drive it & then adjust it further until your AFR is correct on full load with F0 to FF on the bottom row which maximise the resolution of the fuel table. Once you've got the bottom row correct and the scalars you can then start remap the reset of the fuel table.

To merge your AFR log with RoverGauge you need the computer system time stamp in your AFR log instead of the running time from 0. Can you somehow save the exact start time of your AFR logger, maybe from a batch file, and then in Excel calculate the system time from the start time + run time. When you have the system time in both logs you can then merger them in Excel and create a Pivot table to give the AFR at each cell in the fuel table.

Alternatively, I know some people take video clips of RoverGauge & AFR gauge in view together so on play back they can see the AFR at each cell in the main fuel table.

Good Luck, Steve

[stevesprint]

blaze_away said:

Had data set from op and there is significant water temperature issue that needs investigating.It never gets higher than 62

Ad5tar said:

AFR logger puts a full timestamp at the top of the log and then each line is milliseconds since that timestamp. I tried to put it into Excel but didn't invest a lot of time on it, figuring out how to add milliseconds. I'll give it another try.

Arr, I see your system time stamp at the start of your AFR log, just need some clever time addition formula.

Ad5tar said:

I'm a bit of a electronics tech head. I had to de-solder the factory eprom and solder in a socket, which was pretty easy to do. My eprom has a GP on it from factory, I'm curious on what that means?

No idea what the GP means but I’ve seen it before on OEM chips. You’re ECU board looks like an early 14CUX with the MVA5033 chip not the later MVA5033KA but should NOT cause you an issue as you’re running map 1 open loop. There have been reported issues running tunes after R2422 on your earlier 14CUX but only closed loop.

Ad5tar said:

Would anyone have an excel spreadsheet they would like to share so I can modify it to suit my wideband o2 logs?

If you can get your AFR log to look like this you can then use my RG & AFR log merger program or merge the logs on Excel.
2023-06-14_15:05:58.871,13.6
2023-06-14_15:05:58.964,13.5
2023-06-14_15:05:59.042,13.5
2023-06-14_15:05:59.120,13.5
2023-06-14_15:05:59.214,13.5
2023-06-14_15:05:59.292,13.5
2023-06-14_15:05:59.370,13.5
2023-06-14_15:05:59.448,13.7

Your Row Scalar sounds correct as you’re reaching the bottom of the fuel table so just focus on the main multipier.

[stevesprint]

Adam

I’ve worked out in Excel how to add the system time with millisec to your AFR readings with the following, I'll email you the spreadsheet.

Column B = TIME(15,23,32+A5)
Column C = IF(LEFT(RIGHT(A5,2),1)=".",CONCATENATE(RIGHT(A5,1),"00"),CONCATENATE(RIGHT(A5,2),"0"))
Column D = CONCATENATE("2023-06-12_",TEXT(B5,"hh:mm:ss"),".",C5)

However your start time doesn’t contain millisecs and therefore could be out upto 0.9 sec, nevertheless I'll have a go merging the logs you've emailed with your fixed thermostat.

Drive smoothly & steadily while logging with no sudden throttle movements otherwise the throttle enrichment will skew the AFR.

Strange your TunerPro won't update the checksum, I assume the fuel tables load & look ok, what version are you running?
Don’t worry about the checksum fault code in RoverGauge its harmless and simply means your checksum is wrong.

You could always correct your checksum with www.remap-14cux.uk/software/14CUX_Toolkit_V1-2.exe

Good Luck and data log safely

Edited by stevesprint on Saturday 17th June 23:01