Instructions to change fuel maps on 14CUX Griffith, Chimaera

Instructions to change fuel maps on 14CUX Griffith, Chimaera

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Discussion

blitzracing

5,939 posts

175 months

Monday 21st January 2019
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As I understand it Its not quite that simple- the tune covers the entire micro code that the ECU runs on, so later tunes have improvements on the way the ECU controls things like the stepper. The basic fuel map is what matters day to day, and the bit id concentrate on getting right in the first place for your set up.

Have a read of Steve sprints excellent web page with free downloads:

http://www.remap-14cux.uk/bins/

KiwiRRC

3 posts

18 months

Tuesday 22nd January 2019
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blitzracing said:
As I understand it Its not quite that simple- the tune covers the entire micro code that the ECU runs on, so later tunes have improvements on the way the ECU controls things like the stepper. The basic fuel map is what matters day to day, and the bit id concentrate on getting right in the first place for your set up.

Have a read of Steve sprints excellent web page with free downloads:

http://www.remap-14cux.uk/bins/
Thanks- that's awesome. It was Steve's site that I found online and his 3383 that is running sweetly. I just wasn't quite sure how up to date that was and I will have a go with the Aussie and Saudi Maps I found on the Disco for the fun of it. Thanks guys for the great work on this and taking the time to respond its much appreciated.

stevesprint

Original Poster:

1,046 posts

134 months

Monday 28th January 2019
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Dave (Kiwi RRC)

Sorry for the delayed reply, my son keeps distracting me in the garage with his Rover V8 MX5 project.

I’m impressed you successfully socketed your ECU, its not an easy task especially as its a multi-layer PCB, I’m pleased to learn from yourself R3833 was also used in Discos and not exclusive to RRC.

Mark is right the PROM chip contains both, the 5 fuel maps and the program code, which I’m sure you now know, that’s why I’ve merged TVR’s fuel maps with Land Rover’s later code.

KiwiRRC said:
..... is the 3383 about as good as gets for a stock tune for a 1992 RRC 3.9l V8 with no cat and a 14CUX?
YES, even though R3604 is from a 1997 UK 3.9 Disco and must be the very last PROM developed for a UK Vehicle albeit for CATs. This last UK R3604 prom has exactly the same program code and same 5 maps as R3833 but with a few minor tweaks for very cold cranking & cold idle & the minimum temperature to disable closed loop, I’ll add R3604 to my site in case you live in a very cold climate.

There are a few other proms with later PROGRAM CODE than R3383/R3604 but they are for CAT vehicles with special requirements for example

R3365 NAS 94 Defender (contains code optimisation to improve road speed limiter accuracy)
R3452 Japan MGR V8 (Hot climate with extra ECU monitoring CATs temperatures
R3526 NAS 95 Range Rover Classic
R3652 NAS Cold weather upgrade

If you do give the Aussie and Saudi fuel maps a spin let us know how they run.

Best of luck and please let me know if I can be of further assistance.
Steve

KiwiRRC

3 posts

18 months

Friday 15th February 2019
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stevesprint said:
If you do give the Aussie and Saudi fuel maps a spin let us know how they run.
Thanks Steve,
I really appreciate the help. Apologies for the slow reply - as a newbie I get blocked occasionally. Will let you know how I get on. I built a little rotary switch to swap between tune resistors. So far I couldn't spot a difference in the maps code - and haven't noticed a performance difference after a quick play. Might also borrow the original chip. And fortunately I live in New Zealand - so never that cold!

Cheers
Dave

gecko951

1 posts

14 months

Wednesday 29th May 2019
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Many thanks for the ECU firmware update instructions! My 1990 NAS RRC never had its firmware updated by LR and I have found that power delivery and acceleration are so much smoother on the LR 3652 firmware. Idle stability is improved and most importantly I no longer get hesitation/shunting when pushing the pedal to the metal for passing! biggrin

stevesprint

Original Poster:

1,046 posts

134 months

Thursday 30th May 2019
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Gecko
Thanks for your positive feedback, it encourages me to keep my 14CUX efforts going. Please let me know if you need a hand tweaking your map, like increasing the idle or the RPM limiter.



Update (May 2019)
Although this 14CUX effort may appear quiet I’ve been quietly hacking away at the program code this winter and successfully reprogrammed the AC condenser and AC clutch outputs to control my cooling fans in 2 stages at configurable temperature threshold. I’ve put the temperature on/off thresholds in the data section so they can be changed by anyone with a chip programmer and running my cooling fans code enhancement.

I’m also successfully running the bigger 4.6 Bosch MAF sensor by changing the AFM scalar and offset in the fuel map to keep the idle on the second row and full throttle on the bottom row. The 4.6 Bosch MAF also required a full remap and an extra 5 volt reference feed which I took from the throttle POT. I much prefer the Bosch MAF as its electronics are encapsulated inside the cool intake airflow and are more compact which makes room for a heat shield.

I’m now so pleased with the results I’ll tidy up the installation.


The 4.6 Bosch MAF (Part No: 0280 218 010) are available new from your local goodies store including Eurocar Parts and should be available new for a while as the internal hot film sensor (F 00C 2G2 029) is commonly used on BMWs of the same period.

Should you have any questions please do hot hesitate to contact me.

spitfire4v8

3,271 posts

136 months

Friday 31st May 2019
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Interested to see that you've got yours to run to the bottom row of the fuel map with the bosch afm .. I've seen two 5 litre bosch converted cars now with the maf scalar maxed and neither of them reached the bottom row. It's one of the reasons I've delayed moving from 20am to bosch ..
what's the secret!!?? hehe

stevesprint

Original Poster:

1,046 posts

134 months

Sunday 2nd June 2019
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Joolz

No secret, maybe because my 5AM was running at +96% airflow where as the Bosch 4.6 runs at 75% airflow.

Here’s my new 4.6 Bosch MAF from Euro Car Parts, do you know if the part number is correct and the same as the cars you tested.




Here’s a comparison of the AFMs with the inner diameters measured at the narrowest point

3/5AM (54mm) ..................................................... 20AM (70mm) .............................4.6 Bosch MAF (76.5mm)


You can see below my ‘Row Scalar’ is EA, in addition you’ll also notice I’m now running your all new RPM set points without any issues and hope you don’t mind. To pull the idle back up to the second row I had to increase the ‘Row Offset’ at prom offset 1C8 from 1E to 34. The Row Scalar, as you know, is a multiplier and there are 6 per chip, one per fuel map, whereas there is only one ‘Row Offset’ per chip and it shifts the usable range of the fuel table uniformly up and down. For my information, I also change the Ident at the top of the RoverGauge screen to 34B5 so I can quickly see my current ‘Row Offset’ & my fuel table version B5 for Bosch 5, but please don’t analyse this fuel table too closely as it was an old work in progress and now tidied up in B6.


Edited by stevesprint on Sunday 2nd June 15:49

Sardonicus

16,971 posts

176 months

Sunday 2nd June 2019
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Nice work Steve if thats a BMW AMM stocks wont be running out any time soon, I like the fan control changing the outputs thats trick

MPO

263 posts

67 months

Tuesday 25th June 2019
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Hi

What is the default value for the fuel temperature in the 14CUX code if the sensor is disconnected?

Also,

Is it possible to set the this default temperature to something else if wanted and where in the code?


Many thanks

danbourassa

242 posts

92 months

Tuesday 25th June 2019
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Hi MPO,
Just to clear up any confusion before it starts. The LR documentation is wrong about about this. The PDF file 13/14CU AND 14CUX SYSTEMS which is widely available says this about the Fuel Temp on page 85:

As with the engine coolant temperature sensor, a diagnostic trouble code (15 [14CUX only]) is stored when the signal is out of range (0.08V to 4.9V) for longer than 160 milliseconds. No default value is provided by the ECM, however the MIL will illuminate.

Looking at the code near the beginning of the Fuel Temperature Service Routine (fuelTemp.asm), you will see that it is set to a fail condition default value of 71 hex. This equates to 35 C or 95 F. You can change this value to anything you like but be aware that it has a small affect on fueling (maybe this is what you want).

Of course you will have to short or open the sensor wire to trigger a code 15 and get your value substituted in place.
-Dan

davep

1,030 posts

239 months

Tuesday 25th June 2019
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Dan, really good to see you here again!

Apologies but I have a quick question: Could you just remind me how you get a $71 default faulty sensor value to equate to 35 deg C or 95 deg F.

I'm confused since in the code comments it states that the hiFuelTempThreshold parameter and Shutdown routine use a value of "$65 (equates to 40 deg C)" from C0B4 as the threshold for extra fueling on re-start?

Is it really the case that fault 'code 15 faulty sensor' is set prior to the hiFuelTempThreshold level being reached?

danbourassa

242 posts

92 months

Thursday 27th June 2019
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Hi Dave,
The temperature look-up-table for both the coolant sensor and the fuel sensor looks like this:
130,129,127,126,124,123,121,120,118,117,115,114,112,111,109,108,
106,105,104,103,102,101,100, 99, 98, 97, 96, 95, 94, 93, 92, 91,
90, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75,
74, 73, 72, 71, 70, 70, 69, 68, 67, 66, 65, 64, 63, 63, 62, 61,
60, 59, 59, 58, 58, 57, 56, 56, 55, 55, 54, 54, 53, 52, 52, 51,
51, 50, 50, 49, 49, 48, 48, 47, 47, 46, 46, 45, 45, 44, 44, 43,
43, 42, 42, 41, 41, 40, 40, 39, 39, 38, 38, 37, 37, 36, 36, 35,
35, 35, 34, 34, 33, 33, 32, 32, 31, 31, 30, 30, 29, 29, 28, 28,
28, 28, 27, 27, 26, 26, 26, 25, 25, 24, 24, 23, 23, 23, 22, 22,
22, 21, 21, 20, 20, 19, 19, 18, 18, 17, 17, 16, 16, 15, 15, 14,
14, 14, 13, 13, 12, 12, 11, 11, 10, 10, 9, 9, 8, 8, 7, 7,
7, 7, 6, 6, 6, 5, 5, 5, 4, 4, 3, 3, 3, 2, 2, 2,
2, 1, 1, 0, 0, -1, -1, -2, -2, -3, -3, -4, -4, -5, -5, -6,
-6, -6, -7, -7, -8, -8, -8, -9, -9,-10,-10,-11,-11,-11,-12,-12,
-12,-13,-13,-14,-14,-15,-15,-16,-16,-17,-17,-18,-18,-19,-19,-20,
-20,-20,-21,-21,-22,-22,-22,-23,-23,-23,-24,-24,-24,-25,-25,-25

It's formatted 16 by 16, so it's easy to convert. Hex 71 means 8th row down and 2nd column (remember it's zero based).

Value hiFuelTempThreshold is used for storing a high temperature in the battery-backed (non-volatile) area in 14CUX memory. The saved temperature is called hiFuelTemperature. In the case of a very hot restart, the code does something different with the cranking time fueling. I haven't looked at it for a long time but I seem to remember that it was the opposite of what I expected. That is, more fuel instead of less! The thinking was that vapor bubbles in the fuel rail needed to be purged.

All values in the table are valid except 4 values from either end. In other words, you will never see 130,129.127 or 126 (or the last four). Either end will trigger a code 15 and the programmed default will be used instead. This is why shorting or opening the sensor line will trigger the fault. So anyway, I think you bring up a good point. If the default value was changed to something higher than hiFuelTempThreshold it may fool the software into thinking that the engine was shut down with a high underhood temperature and affect an instant restart.

davep

1,030 posts

239 months

Friday 28th June 2019
quotequote all
^^^^^^

Thanks Dan. I really should have scrolled back to earlier pages to get that look-up table info!

So as I understand it: In the event of a faulty fuel temperature sensor (short or open circuit) a default value of $71 (35° C) is set for hiFuelTemperature as is fault code 15. Which means for these conditions the value in hiFuelTempThreshold of $65 (40° C) will never be exceeded, thereby suppressing the extra fuelling feature for very hot under bonnet temperatures.

MPO are you looking to completely suppress the extra fuelling at high temperatures or bring it in earlier to help with hot-start problems? If the later, try tweaking the value at address location C0B4 for a lower temperature using Dan's look-up table.

MPO

263 posts

67 months

Sunday 30th June 2019
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Dan and Dave

Thanks for your responses and info and sorry for my delay in responding… Been Playing smile

Recently, I installed larger Bosch Injectors and a 3 Bar Bosch FPR because my Lucas ones were regularly utilising more than 80% Duty.

I then successfully remapped the fuel table myself using my regular Wideband setup as I have done so for a number of years.

Everything was perfect but the car struggled to start on warm and hot restarts. Quite embarrassing in petrol stations whistle

So, I’ve been tweaking my Current Pre-Cat Cranking Table:-

LC437 DB $00,$12,$1B,$25,$47,$75,$99,$B0,$C8,$DA,$E4,$E8 ; <-- coolant temp sensor reading (low is hot, high is cold)
LC443 DB $0C,$0A,$08,$0D,$19,$2B,$3B,$46,$4E,$59,$69,$75 ; <-- cranking fueling value above zero deg F (stored in X009B)
DB $1E,$10,$07,$0F,$13,$17,$1E,$26,$2C,$31,$39,$44 ; <-- time fueling component, 1 Hz countdown (stored in X009C)



The information you both provided help me identify what would result in disconnecting the temperature sensor.

Since my post I have successfully amended this table and performed many warm, hot and heat soak tests with and without the fuel temperature sensor connected, restarts are now fine... The recent hot weather helped smile

However, I will need to wait until the winter and sub-zero temperatures to test the lower temperature restarts and tweak if necessary.

Thanks for the help

Cheers

Glyn


Edited by MPO on Sunday 30th June 06:26


Edited by MPO on Sunday 30th June 06:33

stevesprint

Original Poster:

1,046 posts

134 months

Wednesday 10th July 2019
quotequote all
MPO said:
Hi
What is the default value for the fuel temperature in the 14CUX code if the sensor is disconnected?
Also,
Is it possible to set the this default temperature to something else if wanted and where in the code?
Many thanks
Dan & Dave
Great to hear from you both and thanks for your help as usual.

Glyn
If you’re looking for a free input to repurpose Dan has confirmed both the ‘heated screen’ and ‘A/C’ inputs can be re-used for other purposes and both input routines do an 8-bit conversion which is ideal but wasteful for off/on switches like A/C and heat screen, if the result is less than 128, the signal is low, otherwise it's high.

However, my cooling fans have always been connected to the heated screen input which lifts the idle for 2 sec when the fans first kick in and works extremely well and therefore recommended.

I was considering using the A/C input to monitor the intake air temperature via the Bosch AFM temperature sensor to lean off the fuel if required due to heat soak. However I’m now less concerned as I’m finding the AFR is less effected by heat soak with the Bosch AFM which could be due to its internal & cool electronics or maybe my new heat shield. I drove into London last week on a really hot and sunny day and was cooked for over an hour in stationary/slow moving traffic due to an accident and my AFR was barely effected by the heat soak.

I’m so impressed with the Bosch AFM I would definitely recommend one but obviously they require a full re-map and it makes room for a heat shield as its smaller on the outside (& bigger on the inside).

RV8 - I'm doing my bit for Global warming

Edited by stevesprint on Wednesday 10th July 23:41

spikep

411 posts

237 months

Wednesday 18th March
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I take it this 1991 ECU is too early to be rechipped and programmed?


blitzracing

5,939 posts

175 months

Thursday 19th March
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You have to cut the chip out and solder a socket in. It requires a solder sucker to remove the legs of the chip and solder, and some white spirit to dissolve the coating on the board. There are two revisions of the board, and if yours is the early one, it won't take the later TVR tunes. PM me if you want the board layout to check or pop a socket in there for you.




spikep

411 posts

237 months

Saturday 21st March
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Hi Blitzracing,

The 5033 chip on the right does not have the KA at the end.

stevesprint

Original Poster:

1,046 posts

134 months

Sunday 22nd March
quotequote all
As you have the earlier MVA5033 PAL chip your best option is to remap R2422 with TunerPro, see below. Please let me know if you need a hand or require any additional R2422 tuning parameters added to TunerPro.

However, as Mark explains you’ll first have to remove your current chip and solder in a socket.

Apparently you can run later chips in 14CUXs with the earlier MVA5033 but only the non cat map 2.