Instructions to change fuel maps on 14CUX Griffith, Chimaera

[100SRV]

Hi all,
I finally got around to putting a socket in my spare 14CU ECU and am now looking at doing some remapping, one area I am interested in is managing the idle speeds for off-road/green laning. The standard ECU has:

1. Base Idle rpm - fixed value
2. Neutral Idle rpm - Active low when automatic transmission in N
3. Screen Idle rpm = Active high, raises idle speed by an offset when heated screen active
4. A/C Idle rpm = Active high, raises idle speed by an offset when HVAC compressor active

Have I understood these correctly and they are enabling an offset which is added to the base idle?
Are they cumulative? i.e. if 2,3 and 4 were active would I get the sum of, for example, -200 + 200 + 50 = base idle +50?

I am considering remapping a chip and experimenting with a 3.9 UK non-cat map with the following changes:
1. Base Idle rpm - fixed value
2. Neutral Idle rpm - Hill descent idle with speed lower than Base idle for short periods
3. Screen Idle rpm = Fast creep with engine speed around 800rpm
4. A/C Idle rpm = Active high, when cooling fans running - no change in offset

2 and 3 would be interlocked by wiring to low range, mutually exclusive and possibly only allowing 2 for a short period if oil pressure is deemed too low.

ETA that is need to set the base idle lower by means of the air bleed screw on the plenum then keep it at the correct idle speed by applying an appropriate offset by switching the neutral signal to 0V so there is good oil pressure for normal use.


 

Edited by 100SRV on Saturday 7th January 23:08

[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

[AllanWorms]

This thread is awesome!

I wish I'd had a 14CUX when this thread was busier!

I have purchased a Japanese market 1997 Land Rover Discovery with the 3.9 V8 14CUX as a bit of a toy. It's has O2 sensors, but the cats have been removed.

Having been through this whole thread and buying some goodies, I've managed to burn 6 versions that I've modified to suit my car (so far!). I already had a Willem Eprom Programmer and Rovergauge (AND the Android version), so I'd have been silly not to see what I can screw up with some EEPROMs and a spare ECU with a lock n load socket .

Thank you guys SO much for working out all the details and sharing so much info! It's really amazing!

My changes so far:

• Changed from 3604 to OpPride 3652 base tune
• Enabled MIL
• Reduced Over-run fuelling to 1000 RPM
• Reduced my main fueling scalar down to 4A38 (I have Bosch EV6 injectors, so reduced this until my LT fuel trims came close to 0, as a bodgy starting point! I don't have an AFR meter... yet!)
• Raised Rev limit to 5502 RPM
• Raised Idle to 625 RPM in D or R, but reduced the Neutral Gear Idle Adjustment to 75, so still 700 RPM in P or N
• Changed Idle Hold-up to 92, to reduce the hold up speed (it would keep pulling and the brakes were needed to creep slowly along my driveway and down hills etc)

I'm nerding out on it, quite a lot

A few questions, if I may?

• What is the "Tracing Map 5 Fuel Table"? In the XDF I have, it only appears for the 2 Cat Fuel Table (4 and 5).

• Can I use the factory O2 sensors to acheive better fuel economy, rather than cat efficiency? My current understanding is that I can lean out the fuel table for low RPM and load, but the O2 sensors will try to alter the trims to run it at stoich - I'm not sure the system is complex enough to do it much better though?

Thanks Soooo much! and no rush to answer - I know everybody is busy and I'm late into the game

Allan.

[Ad5tar]

Hello All,

What an amazing thread.
I've made my way through all of it but alas I do have a couple of questions.

Over here in Oz my son picked up a 2 door '91 Land Rover Discovery. It has the 3.5L V8 petrol.
It had been parked for 4+ years wasn't running when we picked it up.

We have worked on fixing the issues (flush the fuel system, replace MAF, replace injectors, replace fuel pump, convert to bosch module for spark etc)
Turn the clock forward it's on the road (just), but the long story short it's running SUPER rich, fowling plugs etc.

When I picked it up it had 3 failed injectors. We purchased a set of 8 replacement mustang injectors from fleabay and now realize they are rated different to the factory ones. (20lb v 19lb and I'm sure flow better), It was able to drive ok (even though running rich) but it failed a fuel pump, so we installed a new 250ltr Walbro the car is a struggle to drive now, running really really rich killing plugs in couple of days.

The 14CUX had a soldered in eprom chip, I have remove the chip and put a socket on the board and have a couple of UV erasable replacements.

I have a WBo 2Y Wideband O2 Unit and I've just put a bung in the exhaust. I've downloaded the factory ROM from my ECU with Rover Gauge and I hope to get the car running with a better AFR.

I've installed TunerPro on my laptop, but I'm struggling to get my head around it.

I've spent sometime reading about TunerPro but couldn't find much of a "Getting" started guide.

Any help would be greatly appreciated as my son and I are having a blast working on the car, we just need a walking through the basics of TunerPro. I know how to do all the things (burn/erase the eprom etc) but as I said just understanding how to use TunerPro is confusing.

Could I just adjust my injector multiplier instead of modifying the whole fuel table? and if so, where do I do this in TunerPro?
Are the values in HEX? What am I adjusting them too (as in do I convert them to decimal, reduce the number convert back to HEX)
I'm just after a bit of a run through on the basics of TunerPro.

Cheers
Adam and Heath.

[blaze_away]

Before you do anything else get hold of RoverGauge software and a cable and run it up and get some data. Then come back with it and let us know what you see.

Blitzracing here supplies RG stuff for very little ££'s

[Ad5tar]

Thanks for the response.

I'm pretty tech savvy, I've just built up an FTDI cable and connected Rover Gauge and it connected with no issues to my ECU.
I'll setup my wideband and record a drive with it and rovergauge logging.

[blaze_away]

Ad5tar said:

Thanks for the response.

I'm pretty tech savvy, I've just built up an FTDI cable and connected Rover Gauge and it connected with no issues to my ECU.
I'll setup my wideband and record a drive with it and rovergauge logging.

Perfect, when you get back from the drive can you let it idle for 10 minutes and continue to collect data. Once you have the data send it to me and I will analyse it for you. Setup RG
MAF DIRECT
THROTTLE ABSOLUTE
TRIM SHORT TERM
TEMPERATURE MEASUREMENT C

[Ad5tar]

Finally managed to get the car driving.

I have done a run in the car and uploaded the log to here RoverGauge+WB02.xlsx
It's an excel spread sheet with 2 work sheets.
Rovergauge and Wideband.

I'll work on correlating the 2 better, at the moment I can only use RPM to match (or the timestamp from the top + the seconds on the windeband page) (the wideband unit log's RPM direct from the coil).
On cold startup it didn't get above 9-10AFR once warm after a drive it settled around 11AFR

I'm after some guidance on adjusting the fuel map to suit the injectors I have. At the time the injectors were bought they did say they would suit the 3.5L V8. But I now discovered they aren't the same.
This is the details of the injectors I have.
Flow rates @ 43.5psi / 3 bar
20 lb per hour 210 cc per min
EV1 4 hole nozzle

I'm just after some advice on what to adjust in TunerPro. Should I adjust the map table or can I adjust something else to modify the whole map in one go? (and if so how).
I have all the tools to program a new eprom. Just after some advise on making the adjustments.

Cheers
Adam

[Ad5tar]

Hello All,

Well I've managed to get the car almost to a usable AFR.
I have a couple of questions.

I've only reduced my Main Scalar in tuner pro. I've had to reduce this significantly to get my AFR's right.
What is the bi-product of changing this value?
I have gone from 57F4 to 4214 to get my idle AFR around 13.8 and was planning on changing the MAP table to get it around 13.4
Driving the car, I'm still super rich 10.8-11.4 on WOT, crusing is around 12.3, I really want to get this up to 15 odd AFR.

Does changing this scalar mean I'll hit the end of the fuel map table sooner on WOT?
Would I be better off leaving the scalar and modifying the fuel map table?

Sorry for the questions, I've learnt a lot over the last week. Super happy my car isn't fowling plugs now.
But still have a fair bit to go.

Cheers
Adam

[blaze_away]

Offer is still there if you want me to assess the RG data.

One of the most crotical factors to good AFR is the MAF sensor. First it must be responsive to airflow and it needs to be accurate too. It also needs to be sufficiently stable.

In statistical terms it needs to be both Accurate and Precise.

I have thus far found all 4 possible situations with the MAF.

IE
not accurate not precisr = bad AFR
not accurate and precise = bad AFR
accurate not precise = bad AFR
accurate and precise = good AFR

The most common with bad AFR being the 3rd of those. In simple terms there is too much noise with the signal, bit like a speedo that on average is right but it bounces up and down a lot.

[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

[blaze_away]

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

|https://thumbsnap.com/RH2g36hV[/url]

[url]

[blaze_away]

Looking closely at water temperature

Comparison of OP's car vs a normal warm-up cycle. (same x and y scales)

As you can see
1. Normal car was at 90 after about 10 mins (ambient was 14c) then the thermostat and fans control it +/- a couple of degrees.
2. OP's takes about 18 mins to reach 60c then plateaus

I would suspect your thermostat before suspecting the anything to do with the fans.

[Ad5tar]

Thank you Steve and Frank for you responses.

The car is a Land Rover Discover 1 (1991). Being a 4x4 it doesn't run thermo fans, just a clutch fan attached to the water pump.
Alas it is coming into winter for us. (not seeing much over 10-12C during the day).

I'll double check the thermostat isn't stuck open. I did replace it as one of the items when getting the car on the road.

[Ad5tar]

stevesprint said:

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.

Awesome that is what I have done. I'll need to tweak it a bit on full load I'm getting 10.2 to 11.3 AFR which is too rich.
I'm aiming for around 13:1 at full load.
Acceleration I'm trying for around 12.5:1

stevesprint said:

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.

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.

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?

[davep]

Looking at some LR Discovery water temperature charts I have they show normal operating temperatures at 93 deg C, set high for emissions control reasons, so 60 deg is very low. Typically, RV8 engine thermostats are calibrated to open up the full water cooling system at 88 deg C when the engine is warmed up. Some TVRs and LRs do have lower rated thermostats of 82 deg to bring radiator cooling in earlier.

On the LR Discovery the radiator cooling fan's clutch unit is controlled by a dedicated fan control unit, which in turn has a control input from the 14CUX ECU. This might be worth checking to see if the clutch is fully engaging too early? Apologies just seen you have an early Disco 1 so the fan is just viscous clutch controlled, may be bi-metal coil at fault?.

Because of the radiator and front engine layout TVR cooling fans are switched On and Off by an independent Otter switch mounted in the cooling system's swirl pot or in the radiator itself. This thermostatic switch is calibrated to switch On at 92 deg C and Off at 87 deg C. The Otter switch operating is shown quite clearly in Blaze Away's 'normal' ECT chart above.

Good luck with your mapping endeavours Adam.

Edited by davep on Wednesday 14th June 18:31

[Ad5tar]

Woohoo we now have a warm car

Was a slightly stuck open thermostat. (it wasn't closing the last couple of mm's).



Popped in a new one and the car now idles up to temp (90C) and doesn't budge.

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

[Ad5tar]

Hello again (yup I'm a kid in a candy store).

I have hit an issue in TunerPro that I hope someone can help.
I have placed the 14CUX_CHECKSUM2.0.dll in my TunerPro folder but when ever I save my .bin it comes up with the error

Error - One of more checksums could not be updated. Check checksum addressing, etc, for validity.

I also get a MIL light on, before start (goes out once started) and have the checksum fault.

How can I correct this?

[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.

[blaze_away]

New data set from OP post fixing the thermostat, all now looks good on water temperature front