Instructions to change fuel maps on 14CUX Griffith, Chimaera

[haaren]

As the start of this topic is very old, which items do I need to order nowadays, when I search on the original I can only find set of $150+
1 - TOP853 USB universal programmer, I bought mine off ebay for about £30.
If it's still available at above price I can give it a try to do it myself, however I'm not so handy with computers / programming.
Hope someone can give me a help, thank you

[CGCobra]

haaren said:

As the start of this topic is very old, which items do I need to order nowadays, when I search on the original I can only find set of $150+
1 - TOP853 USB universal programmer, I bought mine off ebay for about £30.
If it's still available at above price I can give it a try to do it myself, however I'm not so handy with computers / programming.
Hope someone can give me a help, thank you

I started on this path about 10-11 years ago. At that time I bought a TOP 2008 programmer which, like many Chinesium products, came with limited, badly written, instructions and wrong software. Although I managed to get some capable software I found that this would only work on 16bit versions of Windows.
I had an older laptop which would work but my regular laptop would not. I have got around this by running a 32bit Virtual Machine on my usual laptop, probably not something you want to do if your not so handy with computers.
I have looked into getting a 54bit version of the programmer but they do seem more expensive than the one I bought. Someone did give me some details some time ago of an alternaive programmer, I'll see if I have a record of it.


Edit.
This is that one I was sent some information on:

https://www.ebay.co.uk/itm/187473320331?_skw=tl866...


Bear in mind I have not used this product myself and (again, as with many Chinesium products) you are not guaranteed to get the same product twice so take care!

Edited by CGCobra on Monday 18th August 18:16

Having said all that I'd say you probably first want to get set up with Rovergauge and a comm's cable. Did you already do that?
You will most likely also need a wideband lambda gauge in your exhaust so that you can monitor your starting point and effects of any changes you make.
It seems interest has dropped of somewhat on this thread in recent times but there are still a few of us "playing"

Edited by CGCobra on Monday 18th August 18:19

[andrewbr]

I have the device CGCobra linked above, it's incredibly easy to use once you make the effort to go through the badly-translated documentation to download the programming software and so on.

I'm using the R3652 tune direct from SteveSprint's website which is working great for the car ('93 Chim 400), also highly recommend that. Definitely an improved starting point if you want to play around with things further, or at least mitigate some of the running issues from an older tune while you figure out how to tweak some of the other things that could be improved on the TVR in general (edit: I see you already have RoverGauge to assist you with these diagnoses so that's great).

Edited by andrewbr on Monday 18th August 18:57

[Belle427]

I think the gentleman just wants a chip burnt for him as his existing one is incorrect, not sure who may be able to do that for him.

[CGCobra]

Belle427 said:

I think the gentleman just wants a chip burnt for him as his existing one is incorrect, not sure who may be able to do that for him.

Ah, good point. I didn't see the first post as my browser had paged over to page 73.

If that is what is required I could help out, I'll have another read through the posts tomorrow to try and work out what is being asked.

[Belle427]

CGCobra said:

Belle427 said:

I think the gentleman just wants a chip burnt for him as his existing one is incorrect, not sure who may be able to do that for him.

Ah, good point. I didn't see the first post as my browser had paged over to page 73.

If that is what is required I could help out, I'll have another read through the posts tomorrow to try and work out what is being asked.

Thread is here.
https://www.pistonheads.com/gassing/topic.asp?h=0&...

[haaren]

It's correct I rather buy a ready chip than burn it myself, however when needed I need to get deeper in it and make myself. I will send cobra a private message, already thank you for the support

Edit: it's not possible to send an mail to cobra, please let me know how to proceed.

Edited by haaren on Tuesday 19th August 07:16

Edited by haaren on Tuesday 19th August 07:16

[indigochim]

So is it the "TVR 400 Precat and 400 CAT based on LR R3652 with Extended Fuel Table to 6250RPM" you're after?

I've found that the 62500rpm isn't the case on the one I burnt for myself but happy to try and burn one for you (I've not used my writer in some time so may take a while to get time to setup with my current PC). I tried to email but I suspect you either have the option turned off in your profile or you haven't meet the age/post restriction to email.

[CGCobra]

indigochim said:

So is it the "TVR 400 Precat and 400 CAT based on LR R3652 with Extended Fuel Table to 6250RPM" you're after?

I've found that the 62500rpm isn't the case on the one I burnt for myself but happy to try and burn one for you (I've not used my writer in some time so may take a while to get time to setup with my current PC). I tried to email but I suspect you either have the option turned off in your profile or you haven't meet the age/post restriction to email.

How did you know that "the 62500rpm isn't the case on the one I burnt "? Is that because that limit was not displayed on the RG screen?
I've noticed that is you turn on the ECU and connect with RG before starting the engine you don't get the correct RPM limit displayed.
My take on this is that this limit is read only once on making connection. Prior to the engine start the map RPM limit has not been read.

[haaren]

62500 rpm wil sound incredible but a bit much, a little lower is also ok

If possible I like to have 2 chips, one original 2967 so I can set all correct and avoid troubles and one 3652 with 6250rpm to drive after all issues are solved.
Little upgrades are always welcome

[haaren]

CGCobra said:

RPM limit displayed.

can vary in rg, you never know which number will show up when you get connected

[CGCobra]

haaren said:

Edit: it's not possible to send an mail to cobra, please let me know how to proceed.

I don't know why that would be, I'm not too au-fait with this forum but I think I've had PMs before.
Anyone any ideas?


OK, I think I found the setting for that, you should be able to e-mail me now.

Edited by CGCobra on Tuesday 19th August 20:12

[CGCobra]

haaren said:

can vary in rg, you never know which number will show up when you get connected

I've found that if you connect RG then start the engine you will get the figure in the default settings (5500 IIRC) but if you start the engine then connect RG you will get the value associated with the map in effect. I think there are some other parameters which work this way although I can't remember which off hand. I've looked quite deeply into the code in the PROM and I believe that the parameters for the map chosen (usually) by the tune resistor is only read during processing of the ignition interupt routine (from memory) hence is not 'known' by the ECU until the engine is running or at least turning over creating a spark. This is why I suspect RG only reads certain values once, at start-up, presumably due to reducing un-necessary communications. Time is at a premium with the 14CUX!

[AllanWorms]

For programming, I use:

https://www.mcumall.com/comersus/store/comersus_vi...

I've used it for much more modern stuff too.


For the posts about setting the base idle: If everything is running well, the lower you can set the base idle, the better. I get mine to idle on the base idle screw at about 500 rpm. Then the ECU programmed idle speed takes over. If you run the base idle too high, the ECU doesn't have the resolution to adjust minutely. It needs to be able to adjust up and down.

If the base idle screw is used to adjust the idle, the ECU loses control of the idle and neds up hunting. If setting the base idle with the screws *helps*, thereis something else not quite right, like a vac leak or fuelling issue.

The ECU is supposed to control the idle entirely. Regardless of load, the ECU should always have control of the idle speed.

[indigochim]

CGCobra said:

How did you know that "the 62500rpm isn't the case on the one I burnt "? Is that because that limit was not displayed on the RG screen?
I've noticed that is you turn on the ECU and connect with RG before starting the engine you don't get the correct RPM limit displayed.
My take on this is that this limit is read only once on making connection. Prior to the engine start the map RPM limit has not been read.

Not using RG but the tacho is quite shy of 6k when it's like it hits a limiter.

[davep]

AllanWorms said:

... For the posts about setting the base idle: If everything is running well, the lower you can set the base idle, the better. I get mine to idle on the base idle screw at about 500 rpm. Then the ECU programmed idle speed takes over. If you run the base idle too high, the ECU doesn't have the resolution to adjust minutely. It needs to be able to adjust up and down.

If the base idle screw is used to adjust the idle, the ECU loses control of the idle and neds up hunting. If setting the base idle with the screws *helps*, thereis something else not quite right, like a vac leak or fuelling issue.

The ECU is supposed to control the idle entirely. Regardless of load, the ECU should always have control of the idle speed.

Good point.

On my car, TVR 4.3 BV R2422, I first adjust the base idle screw setting as close as possible to the Base Idle value in the ECU's Fuel Map, which is 800 rpm. I then adjust the screw setting down approximately a quarter of a turn, not going too low since I have an additional load on my car that the ECU doesn't know about. For me this results in a smooth and consistent operating idle.

Bear in mind that the ECU when calculating Target Idle starts with the Base idle value defined in the currently selected fuel map, and assumes the screw setting results in a similar or slightly lower value (set during the initial engine build and tuning). To this it adds rpm to compensate for a number of predefined loads, hrw, AC and so on, plus adjustments for current engine rpm and temperature when required.

For Base Idle values and the various tunes in which they are used see:

http://www.remap-14cux.uk/LR-TVR-settings.html

[CGCobra]

davep said:

Good point.

On my car, TVR 4.3 BV R2422, I first adjust the base idle screw setting as close as possible to the Base Idle value in the ECU's Fuel Map, which is 800 rpm. I then adjust the screw setting down approximately a quarter of a turn, not going too low since I have an additional load on my car that the ECU doesn't know about. For me this results in a smooth and consistent operating idle.

Bear in mind that the ECU when calculating Target Idle starts with the Base idle value defined in the currently selected fuel map, and assumes the screw setting results in a similar or slightly lower value (set during the initial engine build and tuning). To this it adds rpm to compensate for a number of predefined loads, hrw, AC and so on, plus adjustments for current engine rpm and temperature when required.

For Base Idle values and the various tunes in which they are used see:

http://www.remap-14cux.uk/LR-TVR-settings.html

Cheers Dave.

My car is very simple, there are no additional loads, the only 'compensation' is due to the manual gearbox. This adds (by default) 100RPM to the 800RPM base idle hence my idle is normally 900. I would like to lower my idle speed when the car is sitting at idle but not manoeuvring, such as at traffic lights out of gear in an attempt to keep the temperatures under the bonnet down. I've experimented with this using a switch on the clutch and removing the 510ohm 'manual' resistor. When the clutch is pressed the ECU sees it as being in neutral/park hence raises the RPM, when it is release (car obviously out of gear) it lowers the RPM. This allows me to manoeuvre without risk of stalling while keeping the idle low when not in gear.
It does work but while I've been struggling to get a stable idle can be troublesome so I removed it some time ago, hopefully can reinstate soon.

I'm surprised I didn't get a any errors as there is some trapping in the code but presumably I sidestep these due to the way I'm using the clutch.

[CGCobra]

AllanWorms said:

For programming, I use:

https://www.mcumall.com/comersus/store/comersus_vi...

I've used it for much more modern stuff too.


For the posts about setting the base idle: If everything is running well, the lower you can set the base idle, the better. I get mine to idle on the base idle screw at about 500 rpm. Then the ECU programmed idle speed takes over. If you run the base idle too high, the ECU doesn't have the resolution to adjust minutely. It needs to be able to adjust up and down.

If the base idle screw is used to adjust the idle, the ECU loses control of the idle and neds up hunting. If setting the base idle with the screws *helps*, thereis something else not quite right, like a vac leak or fuelling issue.

The ECU is supposed to control the idle entirely. Regardless of load, the ECU should always have control of the idle speed.

Thanks Allan.
With your base idle set to 500 and presumably your ECU value set to 900 (or possibly 800) what %age do you find you stepper possition to be at?

I do have a feeling that there is still "something else not quite right" and I am currently looking to get the car smoke tested for a vac' leak.

[CGCobra]

indigochim said:

Not using RG but the tacho is quite shy of 6k when it's like it hits a limiter.

That may not be your ECU causing that though, hydraulic lifters have a pump up facility which will hold the valves open at high RPM (can't remember the setting but around 6k rings a bell) as a rough and ready rev limiter. Not sure if later, ECU controlled engines, still had this behaviour as the ECU should have taken over this job and of course TVR may have used different ones.

[CGCobra]

Out of interest where do you guys get your EEPROM chips and around how much do you pay?

When I first started doing this I bought about 10 of them and don't remember paying too much for them, just looked a pricing some up and they are £13.52 inc VAT (slightly cheaper if 10+ bought), don't recall paying over £100 for my original supply as I may have thought twice, perhaps prices have hiked over the last 8 years or so. What prices haven't!

I buy them from CPC which is a branch of Farnell as they are local to me so easy to go in and buy with no waiting for postage, maybe I need to shop around.