Discussion
I know this topic has been covered once or twice on this forum 
but I have a simple question.
I have the ever present problem of shunting at the moment and I was hoping to find a way forward.
I spoke to Neil Graner near Tetbury (TVR Specialist) and he suggested I speak to Mark Adams who I am led to believe can help with a new chip + a rolling road session?
Does anyone have his contact details please?
but I have a simple question.I have the ever present problem of shunting at the moment and I was hoping to find a way forward.
I spoke to Neil Graner near Tetbury (TVR Specialist) and he suggested I speak to Mark Adams who I am led to believe can help with a new chip + a rolling road session?
Does anyone have his contact details please?
http://www.tornadosystems.com/
But please dont think that a chip change is a guaranteed fix- otherwise the issue would have been resolved years ago. There are multiple factors that can cause shunting, some being as simple as poor ignition, or wrong fuelling due to a sesor input being wrong, or the ECU in get you home mode.
But please dont think that a chip change is a guaranteed fix- otherwise the issue would have been resolved years ago. There are multiple factors that can cause shunting, some being as simple as poor ignition, or wrong fuelling due to a sesor input being wrong, or the ECU in get you home mode.
It has been suggested to me that the main cause of shunting is the ignition timing/advance jumping around at low revs due to distributor design and/or wear. This has lead me to considering an Aldon Amethyst ignition control as i cant be arsed to change the whole management system. Can anyone back this as I've also read fuelling is the problem.
Any comments on this?
Any comments on this?
Mine shunts now and again. I believe its common.
However, although the Tornado system is popular, things have moved on and the Tornado chip could be seen as an expensive and closed approach compared to some other aftermarket options. Blitz knows what he's talking about, plus there is loads of stuff on here covering ignition and fuelling, that would probably work out cheaper than the Tornado approach in the long run.
However, although the Tornado system is popular, things have moved on and the Tornado chip could be seen as an expensive and closed approach compared to some other aftermarket options. Blitz knows what he's talking about, plus there is loads of stuff on here covering ignition and fuelling, that would probably work out cheaper than the Tornado approach in the long run.
Thanks for the info guys,
My car is going in soon for a check over to see if every thing is as it should be.
I guess I'll then need to look further afield.
It's a real shame, because otherwise its a great car and as a lot of my miles are done in town it makes it a bit of a ball ache to drive smoothly.
Have a good (long) weekend
Mark
My car is going in soon for a check over to see if every thing is as it should be.
I guess I'll then need to look further afield.
It's a real shame, because otherwise its a great car and as a lot of my miles are done in town it makes it a bit of a ball ache to drive smoothly.
Have a good (long) weekend
Mark
I spent many hours trying to come up with a cure. Certainly on cars that run catalysts, you can reduce the shunting by switching to the non catalysts map- but that raises a whole range of new issues. You can also reduce it by lifting the AFM output at the point it starts by around 150mv- this effectively richens the mixture for a short period, but the ECU is quick to lean it off again, so you cant make a permanent fix this way. I think even if you richen the mixture in the fuel map, the same will happen. I think there may be some advantage to using a piggy back digital unit to remap the AFM output- to provide a sharp increase in fueling just at the shunting point, and nothing more, so the ECU cant really compensate. The piggy back Im currently playing with has a 60 rpm steps for the remap so it can be far more precise than the cars original fuel map, and its only £100, which makes chipping kind of expensive, especially as you need just a laptop to program it. Ive fitted the unit, but have problems with it locking up due to spikes on my ignition, but hopefully some resitive plugs will cure this- Ill find out this weekend.
Ive not heard the one about the timing jumping around- but basically anything that improves the burn, be it fuel, airflow or ignition can reduce the shunting.
Ive not heard the one about the timing jumping around- but basically anything that improves the burn, be it fuel, airflow or ignition can reduce the shunting.
Edited by blitzracing on Friday 24th May 19:42
I had that problem just over a week ago my car started shunting whilst out for a run and it had never done it before. Took the car home allowed it to cool and checked it again and it ran fine. Went for another run and started shunting again whilst hot. I have the land rover fault code unit plugged in all the time but it failed to pick up that the throttle pot resistance was breaking down when very hot. I would not have picked it up if it wasn't for Rover gauge and watching it online as it was intermittent and did not latch in the ECU as I would expect. So I would suggest if you have a laptop getting Rover gauge and the cable from Blitz (its great) and having a look at what the ecu is actually getting back from the sensors.
BP6ES spark plugs transformed my car ... one of the best mods I've done.
http://www.mister-solutions.co.uk/product/bp6es-ng...
http://www.mister-solutions.co.uk/product/bp6es-ng...
Jonny_b said:
BP6ES spark plugs transformed my car ... one of the best mods I've done.
http://www.mister-solutions.co.uk/product/bp6es-ng...
Not recommended for the 500 apparently.http://www.mister-solutions.co.uk/product/bp6es-ng...
chris1972 said:
I've got Rovergauge, but all I get is an ECU Checksum error. I'm planning on heading over to see Blitz in the second half of June, so may get a little progress on the situation. One thing it does make you realise is how inaccurate the temp gauge is!
Yours has been f
ked around with chips and injectors jojackson4 said:
Yours has been fked around with chips and injectors
Looking at the receipts, the injectors were originally mapped in. It's the replacement ECU it had afterwards that hasn't been done... I'm surmising... I have been looking at after market stuff. I can't bring myself to pay £500+ for a 14cux remap. ked around with chips and injectors 
chris1972 said:
jojackson4 said:
Yours has been fked around with chips and injectors
Looking at the receipts, the injectors were originally mapped in. It's the replacement ECU it had afterwards that hasn't been done... I'm surmising... I have been looking at after market stuff. I can't bring myself to pay £500+ for a 14cux remap. ked around with chips and injectors Going down ecu next time the snow falls
jojackson4 said:
Setup setup setup get it right job done
Get rover gauge it makes I easy
Not so, the main cause of the surging is cross contamination between cylinders, trumpets & the plenum some do it noticeably some dont, when you throw in lean mixtures, different camshafts inc wear & tear etc things just get worse ........ Generally.Get rover gauge it makes I easy
chris1972 said:
Looking at the receipts, the injectors were originally mapped in. It's the replacement ECU it had afterwards that hasn't been done... I'm surmising... I have been looking at after market stuff. I can't bring myself to pay £500+ for a 14cux remap.
The £500, if you're lucky, you'll pay will be nothing to the frustration of getting hold of the expert!I think the days of needing a specialist re-chip are numbered with Piggy back units on the AFM. Its been done for years already with the Unichip device, but it was expensive to start with, and Unichip where far from helpful- their attitude was you take it to one of our dealers to get the work done, no scope for DIY at all.
Rechipping the 14CUX is a pain, as the fuel map is not in re-writable device. This means you either have to take map, read it onto a PC, modify it, and then program a test device (time consuming) or use an "eprom emulator" chip that plugs into the ECU, that looks like the standard fuel chip to the ECU, but it has the option to reprogram it on the fly, so map modifications take much less time between tests. The set up costs to do this are not cheap, modification software is around £1k, plus an emulator is about £200, plus rolling road time and the required expertise. It MAY now be possible to use RoverGauge to read the relevant map location of RPM vs load on the rollers and pick up when the fueling is wrong for specific map locations,copy the map then modify it with a simple hex editor program, and then reprogram a new Eprom. This process will alter the check sum value in the chip, and make the ECU throw a fault code, so the check sum has to be rewritten as well- I dont know how this is calculated- nor it would appear do some of the chippers, as Ive seen the check sum errors on a couple of remaps now (Not MA ones). Ive never bothered to try remapping, as I doubt Id ever get my money back on the investments (not being a garage or having a rolling road either does not help.
), even if I knew how to do it.
So the upshot is it will be easier just to adjust the airflow voltage up or down so the ecu simply uses a different load value in its normal map and alters the fueling accordingly.
The difficult bit is the lambda correction will constantly try and compensate to keep the mixture in line, once you have made any changes, and it takes at least 2.5 minutes for the long term trim to set at idle after each change- so again very time consuming. I HOPE, that by disconnecting the lambda probes all together, together with an ECU reset to bring the long term trim to zero, you can then adjust the AFM voltage to get the fueling as required without compensation. Without the probes the ECU should not throw a fault code, as it only turns on the Lambda circuits once it gets a signal, so no signal, no faults- hopefully .....
Once you have got the fueling as required, the ECU will only have to make very small corrections when the lambda's are reconnected, and smaller corrections means better fueling.
Well that's the theory anyway.....
Rechipping the 14CUX is a pain, as the fuel map is not in re-writable device. This means you either have to take map, read it onto a PC, modify it, and then program a test device (time consuming) or use an "eprom emulator" chip that plugs into the ECU, that looks like the standard fuel chip to the ECU, but it has the option to reprogram it on the fly, so map modifications take much less time between tests. The set up costs to do this are not cheap, modification software is around £1k, plus an emulator is about £200, plus rolling road time and the required expertise. It MAY now be possible to use RoverGauge to read the relevant map location of RPM vs load on the rollers and pick up when the fueling is wrong for specific map locations,copy the map then modify it with a simple hex editor program, and then reprogram a new Eprom. This process will alter the check sum value in the chip, and make the ECU throw a fault code, so the check sum has to be rewritten as well- I dont know how this is calculated- nor it would appear do some of the chippers, as Ive seen the check sum errors on a couple of remaps now (Not MA ones). Ive never bothered to try remapping, as I doubt Id ever get my money back on the investments (not being a garage or having a rolling road either does not help.
), even if I knew how to do it.So the upshot is it will be easier just to adjust the airflow voltage up or down so the ecu simply uses a different load value in its normal map and alters the fueling accordingly.
The difficult bit is the lambda correction will constantly try and compensate to keep the mixture in line, once you have made any changes, and it takes at least 2.5 minutes for the long term trim to set at idle after each change- so again very time consuming. I HOPE, that by disconnecting the lambda probes all together, together with an ECU reset to bring the long term trim to zero, you can then adjust the AFM voltage to get the fueling as required without compensation. Without the probes the ECU should not throw a fault code, as it only turns on the Lambda circuits once it gets a signal, so no signal, no faults- hopefully .....
Once you have got the fueling as required, the ECU will only have to make very small corrections when the lambda's are reconnected, and smaller corrections means better fueling.
Well that's the theory anyway.....
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