XJR6 Engine ECU Successfully Remapped
#21
05-12-2012, 06:33 AM
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I thought that some of you would be interested to read that I have now succeeded in remapping an XJR6 Engine ECU. I have spent the morning driving my 95MY manual XJR6 fitted with an engine ECU that has revised ignition and fuelling maps that I have created myself.
Last weekend I removed the standard ECU from my car and dismantled it. I removed the two EPROMs (Erasable Programmable Read Only Memory), otherwise known as “chips”, from the sockets that are soldered onto the printed circuit boards. I copied the hexadecimal data from these chips into a PC. I was then able to manipulate this data to advance the ignition timing and reduce the level of fuelling over-enrichment.
I then loaded the revised hexadecimal files into two new chips. These chips were then fitted to an ECU that had previously been fitted to a 3.2L X300. It is this ECU which I now have fitted to my XJR6.
Using this same process, I can, in principle, change any of the data in the ECU. There are over 600 constants and 200 maps in the ECU so the possibilities for making changes are enormous. The key is being able to find where any individual map or constant is located in amongst all the data and knowing by how much to change it. Fortunately, as I was originally responsible for creating much of this data when I worked at Jaguar, I have a big head start compared with anybody else trying to perform this process. I hesitate to refer to what I am doing as “chipping the ECU”, since the companies who “chip” cars rarely have access to the “inside information” that has allowed me to reprogramme these ECUs. Nonetheless, it is a term with which many of you are no doubt familiar.
I normally assess potential improvements in engine performance by measuring in-gear acceleration times. It is important to perform the tests on a level road, with the car at minimum kerb weight, AC off and at a typical ambient temperature in order to make comparisons. I log vehicle speed using software on a laptop PC connected to the car’s diagnostic connector.
From these measurements I have calculated that the in gear acceleration times over the full engine speed range has reduced by 7% compared with original road test of this car. I think this is quite an achievement for a car which is 17years old and has no mechanical modifications that would improve its performance.
I will be developing further changes to maps in the ECU to improve performance and fuel economy in the coming months. If anyone is interested in having their ECU reprogrammed then post your questions here or feel free to contact me directly.
I shall be concentrating my effort on reprogramming ECUs for XJR6 vehicles, as these tend to be driven by owners interested in high performance cars, but it would be possible to apply the same process to the ECUs for naturally aspirated 6 cylinder X300 cars (X304).
I will be continuing to offer my revised crank sensor bracket as an alternative method of providing increased ignition advance for all AJ6 and AJ16 engines.
Last weekend I removed the standard ECU from my car and dismantled it. I removed the two EPROMs (Erasable Programmable Read Only Memory), otherwise known as “chips”, from the sockets that are soldered onto the printed circuit boards. I copied the hexadecimal data from these chips into a PC. I was then able to manipulate this data to advance the ignition timing and reduce the level of fuelling over-enrichment.
I then loaded the revised hexadecimal files into two new chips. These chips were then fitted to an ECU that had previously been fitted to a 3.2L X300. It is this ECU which I now have fitted to my XJR6.
Using this same process, I can, in principle, change any of the data in the ECU. There are over 600 constants and 200 maps in the ECU so the possibilities for making changes are enormous. The key is being able to find where any individual map or constant is located in amongst all the data and knowing by how much to change it. Fortunately, as I was originally responsible for creating much of this data when I worked at Jaguar, I have a big head start compared with anybody else trying to perform this process. I hesitate to refer to what I am doing as “chipping the ECU”, since the companies who “chip” cars rarely have access to the “inside information” that has allowed me to reprogramme these ECUs. Nonetheless, it is a term with which many of you are no doubt familiar.
I normally assess potential improvements in engine performance by measuring in-gear acceleration times. It is important to perform the tests on a level road, with the car at minimum kerb weight, AC off and at a typical ambient temperature in order to make comparisons. I log vehicle speed using software on a laptop PC connected to the car’s diagnostic connector.
From these measurements I have calculated that the in gear acceleration times over the full engine speed range has reduced by 7% compared with original road test of this car. I think this is quite an achievement for a car which is 17years old and has no mechanical modifications that would improve its performance.
I will be developing further changes to maps in the ECU to improve performance and fuel economy in the coming months. If anyone is interested in having their ECU reprogrammed then post your questions here or feel free to contact me directly.
I shall be concentrating my effort on reprogramming ECUs for XJR6 vehicles, as these tend to be driven by owners interested in high performance cars, but it would be possible to apply the same process to the ECUs for naturally aspirated 6 cylinder X300 cars (X304).
I will be continuing to offer my revised crank sensor bracket as an alternative method of providing increased ignition advance for all AJ6 and AJ16 engines.
#22
05-12-2012, 06:37 PM
XJREngineer
Last year I converted my 1997 Jaguar XJ6 to an XJR6 from a 1995 donor car, switching out the entire engine, gearbox, engine wiring harness and ECU's. I had a small problem with the after cat O2 sensors as I had crossed the plugs over (even though both plugs fit into each others receptors). Once that was sorted that car has been working great...that is until recently. When the car is cold it runs fine, all be it with a minor miss-fire on one of the cylinders. When it warms up it is constantly miss-firing/backfiring and will cut out almost immediately. The engine waring light comes on when it does this, but then goes back off again as it attempts to recover. We have plugged in a diagnostics computer and when it is cold the computer can see the various info of the ECU. When the car starts to misfire/engine light on, the diagnostics computer cannot see any of the information from the ECU. My colleague, who's diagnostics computer we are using, has suggested that the ECU is faulty and as it is getting hotter is causing the issue. Does this sound like a plausible explanation for these symptoms. If it is the ECU will have to obtain another one or at least the chips. P.S I am located in Florida, USA (although I am from Staffordshire) and the car is therefor American Spec.
If required could I use an ECU from a UK Jaguar XJR6.
Last year I converted my 1997 Jaguar XJ6 to an XJR6 from a 1995 donor car, switching out the entire engine, gearbox, engine wiring harness and ECU's. I had a small problem with the after cat O2 sensors as I had crossed the plugs over (even though both plugs fit into each others receptors). Once that was sorted that car has been working great...that is until recently. When the car is cold it runs fine, all be it with a minor miss-fire on one of the cylinders. When it warms up it is constantly miss-firing/backfiring and will cut out almost immediately. The engine waring light comes on when it does this, but then goes back off again as it attempts to recover. We have plugged in a diagnostics computer and when it is cold the computer can see the various info of the ECU. When the car starts to misfire/engine light on, the diagnostics computer cannot see any of the information from the ECU. My colleague, who's diagnostics computer we are using, has suggested that the ECU is faulty and as it is getting hotter is causing the issue. Does this sound like a plausible explanation for these symptoms. If it is the ECU will have to obtain another one or at least the chips. P.S I am located in Florida, USA (although I am from Staffordshire) and the car is therefor American Spec.
If required could I use an ECU from a UK Jaguar XJR6.
What you describe sounds like an ignition coil problem. Sometimes the AJ16 has a propensity for the electronics going haywire due to failed coils and the backfeed or spikes induced when they fail. You need to try and pin down what cylinders are misfiring. Just for grins, take your coil cover off at night, and get the engine to begin misfiring. Watch all the coils a see if you see any light show going on down in the epoxy. If you see any, that one is junk.
Good luck!
#23
05-13-2012, 05:14 AM
Hi Johnny,
I don't LNB1410EB/511 which is for a 1996MY emission spec C or E car. However, I can supply something that coulkd replace it. The part that I have in mind is LNA1410HD/514. It is from an earlier 95MY UK spec auto XJR6. I just need to check that somebody else doesn't need it first. Alternatively I can get an ECU from a naturally aspirated car and reprogramme it as an XJR6.
I don't LNB1410EB/511 which is for a 1996MY emission spec C or E car. However, I can supply something that coulkd replace it. The part that I have in mind is LNA1410HD/514. It is from an earlier 95MY UK spec auto XJR6. I just need to check that somebody else doesn't need it first. Alternatively I can get an ECU from a naturally aspirated car and reprogramme it as an XJR6.
#24
05-14-2012, 08:07 AM
Daz,
What you describe sounds like an ignition coil problem. Sometimes the AJ16 has a propensity for the electronics going haywire due to failed coils and the backfeed or spikes induced when they fail. You need to try and pin down what cylinders are misfiring. Just for grins, take your coil cover off at night, and get the engine to begin misfiring. Watch all the coils a see if you see any light show going on down in the epoxy. If you see any, that one is junk.
Good luck!
What you describe sounds like an ignition coil problem. Sometimes the AJ16 has a propensity for the electronics going haywire due to failed coils and the backfeed or spikes induced when they fail. You need to try and pin down what cylinders are misfiring. Just for grins, take your coil cover off at night, and get the engine to begin misfiring. Watch all the coils a see if you see any light show going on down in the epoxy. If you see any, that one is junk.
Good luck!
Darren
#25
05-14-2012, 12:55 PM
Thank you for your reply Steve. As mentioned, the issue only occurs when the car is driven and gets hot. The temperature gauge reads normal. When the fault occurs it is like the ignition is being switched off-and-on as the tachometer needle drops to 0 (like the electric power has been cut) and then recovers. I will try what you have suggested to see if it is a bad coil, but could a single bad coil be causing such a serious fault. Thank you again.
Darren
Darren
Weird, I know, but that's what can happen. I'm not excluding other things as the cause, but the coils can cause real headaches.
Good luck!
#26
05-15-2012, 04:17 AM
Thank you Steve. That is exactly what is happening. The dash lights are all lighting up like a christmas tree. Even the airbag warning light comes on. I noticed that if I rev it up to 5000 rpm it is not as bad. I will get a replacement set of coils and see what happens. Thanks again.
Darren.
Darren.
#27
05-15-2012, 09:01 AM
Thank you Steve. That is exactly what is happening. The dash lights are all lighting up like a christmas tree. Even the airbag warning light comes on. I noticed that if I rev it up to 5000 rpm it is not as bad. I will get a replacement set of coils and see what happens. Thanks again.
Darren.
Darren.
Good luck!
#28
09-12-2012, 03:09 AM
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XJR engineer
Hi XJR engineer. I am new to this site. I am an experienced vehicle electrician with programming ability (day job, but for something else other than cars). I am assisting a friend who is building a "special" race car with an engine from a 1995 xjr. I have to do the wiring. Looking at the diagrams it would appear that there is a fuelling inhibit data stream from the security module to the ecm. I need this removed. Can you help? The donor car was also an auto, and we want to run it as manual. Will the auto ecu work ok?
Thanks for your time in advance
Thanks for your time in advance
#29
09-12-2012, 08:28 AM
You have correctly identified that the engine ECU has an immobiliser function. The std ECU will not run without the security ECU present. I can offer some replacements EPROMs to fit in the engine ECU. These have been programmed to run the engine without receiving a signal from the security ECU. They were specifically developed for racing applications and include configuration for a manual transmission, higher than std idle speed and increased engine braking on overrun. You can email me direct on anystodart@metronet.co.uk for more details.
#31
09-13-2012, 05:18 PM
#33
12-13-2012, 09:03 PM
I thought that some of you would be interested to read that I have now succeeded in remapping an XJR6 Engine ECU. I have spent the morning driving my 95MY manual XJR6 fitted with an engine ECU that has revised ignition and fuelling maps that I have created myself.
Last weekend I removed the standard ECU from my car and dismantled it. I removed the two EPROMs (Erasable Programmable Read Only Memory), otherwise known as “chips”, from the sockets that are soldered onto the printed circuit boards. I copied the hexadecimal data from these chips into a PC. I was then able to manipulate this data to advance the ignition timing and reduce the level of fuelling over-enrichment.
I then loaded the revised hexadecimal files into two new chips. These chips were then fitted to an ECU that had previously been fitted to a 3.2L X300. It is this ECU which I now have fitted to my XJR6.
Using this same process, I can, in principle, change any of the data in the ECU. There are over 600 constants and 200 maps in the ECU so the possibilities for making changes are enormous. The key is being able to find where any individual map or constant is located in amongst all the data and knowing by how much to change it. Fortunately, as I was originally responsible for creating much of this data when I worked at Jaguar, I have a big head start compared with anybody else trying to perform this process. I hesitate to refer to what I am doing as “chipping the ECU”, since the companies who “chip” cars rarely have access to the “inside information” that has allowed me to reprogramme these ECUs. Nonetheless, it is a term with which many of you are no doubt familiar.
I normally assess potential improvements in engine performance by measuring in-gear acceleration times. It is important to perform the tests on a level road, with the car at minimum kerb weight, AC off and at a typical ambient temperature in order to make comparisons. I log vehicle speed using software on a laptop PC connected to the car’s diagnostic connector.
From these measurements I have calculated that the in gear acceleration times over the full engine speed range has reduced by 7% compared with original road test of this car. I think this is quite an achievement for a car which is 17years old and has no mechanical modifications that would improve its performance.
I will be developing further changes to maps in the ECU to improve performance and fuel economy in the coming months. If anyone is interested in having their ECU reprogrammed then post your questions here or feel free to contact me directly.
I shall be concentrating my effort on reprogramming ECUs for XJR6 vehicles, as these tend to be driven by owners interested in high performance cars, but it would be possible to apply the same process to the ECUs for naturally aspirated 6 cylinder X300 cars (X304).
I will be continuing to offer my revised crank sensor bracket as an alternative method of providing increased ignition advance for all AJ6 and AJ16 engines.
Last weekend I removed the standard ECU from my car and dismantled it. I removed the two EPROMs (Erasable Programmable Read Only Memory), otherwise known as “chips”, from the sockets that are soldered onto the printed circuit boards. I copied the hexadecimal data from these chips into a PC. I was then able to manipulate this data to advance the ignition timing and reduce the level of fuelling over-enrichment.
I then loaded the revised hexadecimal files into two new chips. These chips were then fitted to an ECU that had previously been fitted to a 3.2L X300. It is this ECU which I now have fitted to my XJR6.
Using this same process, I can, in principle, change any of the data in the ECU. There are over 600 constants and 200 maps in the ECU so the possibilities for making changes are enormous. The key is being able to find where any individual map or constant is located in amongst all the data and knowing by how much to change it. Fortunately, as I was originally responsible for creating much of this data when I worked at Jaguar, I have a big head start compared with anybody else trying to perform this process. I hesitate to refer to what I am doing as “chipping the ECU”, since the companies who “chip” cars rarely have access to the “inside information” that has allowed me to reprogramme these ECUs. Nonetheless, it is a term with which many of you are no doubt familiar.
I normally assess potential improvements in engine performance by measuring in-gear acceleration times. It is important to perform the tests on a level road, with the car at minimum kerb weight, AC off and at a typical ambient temperature in order to make comparisons. I log vehicle speed using software on a laptop PC connected to the car’s diagnostic connector.
From these measurements I have calculated that the in gear acceleration times over the full engine speed range has reduced by 7% compared with original road test of this car. I think this is quite an achievement for a car which is 17years old and has no mechanical modifications that would improve its performance.
I will be developing further changes to maps in the ECU to improve performance and fuel economy in the coming months. If anyone is interested in having their ECU reprogrammed then post your questions here or feel free to contact me directly.
I shall be concentrating my effort on reprogramming ECUs for XJR6 vehicles, as these tend to be driven by owners interested in high performance cars, but it would be possible to apply the same process to the ECUs for naturally aspirated 6 cylinder X300 cars (X304).
I will be continuing to offer my revised crank sensor bracket as an alternative method of providing increased ignition advance for all AJ6 and AJ16 engines.
my mom passed on last year and i inherited her 1995 xj6, i had it repainted, new keather, tires brakes, suspension shocks etc.
i am impressed with the handling of this little car.
so i want to put a centrifugal supercharger on it. i have done it already on my 2004 towncar ( i collect cars, i have 9 including my wife and daughter). on the town car was easy because i could buy a software that allowed me to reprogram the ecu for the new fuel injectors, MAF and fuel pump.
for the xj6 i have the added complexity that i don't have tuning software for it.
is there software available to tune these cars? also the car does not have an OBDII ( i think it has an OBDI) . any thoughts on this?
#34
12-13-2012, 09:45 PM
i am an engineer and tackle some pretty complex projects, for fun.
my mom passed on last year and i inherited her 1995 xj6, i had it repainted, new keather, tires brakes, suspension shocks etc.
i am impressed with the handling of this little car.
so i want to put a centrifugal supercharger on it. i have done it already on my 2004 towncar ( i collect cars, i have 9 including my wife and daughter). on the town car was easy because i could buy a software that allowed me to reprogram the ecu for the new fuel injectors, MAF and fuel pump.
for the xj6 i have the added complexity that i don't have tuning software for it.
is there software available to tune these cars? also the car does not have an OBDII ( i think it has an OBDI) . any thoughts on this?
my mom passed on last year and i inherited her 1995 xj6, i had it repainted, new keather, tires brakes, suspension shocks etc.
i am impressed with the handling of this little car.
so i want to put a centrifugal supercharger on it. i have done it already on my 2004 towncar ( i collect cars, i have 9 including my wife and daughter). on the town car was easy because i could buy a software that allowed me to reprogram the ecu for the new fuel injectors, MAF and fuel pump.
for the xj6 i have the added complexity that i don't have tuning software for it.
is there software available to tune these cars? also the car does not have an OBDII ( i think it has an OBDI) . any thoughts on this?
I can't help you with the ECU software, but I can tell you the 1995's were OBDII compliant one year early. However the implementation wasn't complete. Some of the PID's don't translate as expected in scantools. The fuel trims for instance seem to read 0-100 with neutral being 45-50; instead of neutral being zero and reading plus or minus values. The MAF seems to be a decimal or two off also. I think 6gm/sec reads .06 on a scantool. Some of the monitors were not very sensitive either; getting a 1995 to set a misfire code can be a challenge sometimes, too. Other than silly stuff like that, if it's a US car, it's OBDII.
Good luck with your car, you fell into one of the best ones Jaguar ever built.
Cheers,
#35
12-14-2012, 12:54 AM
Senior Member
re ecu remap
I have had my ECU remapped by XJR engineer for quite a while now 20,000 k,s to be exact it has brought the car into the 21st century very well
I also have a full headers to tailpipe system cold air induction and Johnson inter-cooler pump and XJR engineers front sway bar links and 3,58 diff gears my car is probably the the fastest XJR I6 in Queensland since the mods
I have consistently seen higher top speeds better economy better city driveability and no embarrassment against BMW,s or Benz,s either
just astonished looks from those drivers
You can ask Andy a million questions but my car is the proof of the pudding his stuff works and works well if he lived in Australia I would be at his place just to see what he comes up with next for these cars
If it hadn't been for his invaluable input over the years I would have scrapped this car years ago
I have tried to upload the dyno video but the file is to big the look on the guys faces when we put my XJR on the dyno was priceless
I also have a full headers to tailpipe system cold air induction and Johnson inter-cooler pump and XJR engineers front sway bar links and 3,58 diff gears my car is probably the the fastest XJR I6 in Queensland since the mods
I have consistently seen higher top speeds better economy better city driveability and no embarrassment against BMW,s or Benz,s either
just astonished looks from those drivers
You can ask Andy a million questions but my car is the proof of the pudding his stuff works and works well if he lived in Australia I would be at his place just to see what he comes up with next for these cars
If it hadn't been for his invaluable input over the years I would have scrapped this car years ago
I have tried to upload the dyno video but the file is to big the look on the guys faces when we put my XJR on the dyno was priceless
#36
12-14-2012, 02:46 AM
Veteran Member
#37
12-14-2012, 02:47 AM
Veteran Member
#38
12-14-2012, 11:45 AM
Hi Aldol,
XJRguy has already confirmed that X300s are OBDII compliant, albeit with a few bugs in the software. Incidentally, the airflow rate is measured in units of 0.1gm/sec.
I don't know of anyone other than me who replrogrammes ECUs for AJ16 engines, but then I would say that wouldn't I. Seriously, there isn't really enough demand for anyone to make a business out of modifiying these engines. If it wasn't for the fact that I wasn modifying my own cars I couldn't justify the time I have spent remapping the ECU.
As you have obviously spent quite a lot of time and effort on your XJ6 I assume that simply swapping it for an XJR6 is out of the question. However, a simpler solution than reprogramming your ECU would be to fit an ECU from an XJR6 along with the MAF and injectors, unless you think your centrifugal compressor is going to flow more that 1018kg/hr of airflow. Personally, I would be very cooncerned that your engine is going to be extremely knock limited if you retain the 10.0:1 compression ratio and fit a supercharger. The AJ16 supercharged engine has an 8.5:1 compression ratio and an ignition map to match. However, even if you use the ECU from an XJR6 with your modified engie, the ignition is likely to be far too advanced for the std AJ16SC ignition map. Your would certainly be testing the knock control system to the limit even if you ran it on the highest octane fuel that you can buy from gas stations.
Good luck with your project.
Hi Plums,
I'm sorry but I don't do any work on any versions of the Jaguar V8 engines.
XJRguy has already confirmed that X300s are OBDII compliant, albeit with a few bugs in the software. Incidentally, the airflow rate is measured in units of 0.1gm/sec.
I don't know of anyone other than me who replrogrammes ECUs for AJ16 engines, but then I would say that wouldn't I. Seriously, there isn't really enough demand for anyone to make a business out of modifiying these engines. If it wasn't for the fact that I wasn modifying my own cars I couldn't justify the time I have spent remapping the ECU.
As you have obviously spent quite a lot of time and effort on your XJ6 I assume that simply swapping it for an XJR6 is out of the question. However, a simpler solution than reprogramming your ECU would be to fit an ECU from an XJR6 along with the MAF and injectors, unless you think your centrifugal compressor is going to flow more that 1018kg/hr of airflow. Personally, I would be very cooncerned that your engine is going to be extremely knock limited if you retain the 10.0:1 compression ratio and fit a supercharger. The AJ16 supercharged engine has an 8.5:1 compression ratio and an ignition map to match. However, even if you use the ECU from an XJR6 with your modified engie, the ignition is likely to be far too advanced for the std AJ16SC ignition map. Your would certainly be testing the knock control system to the limit even if you ran it on the highest octane fuel that you can buy from gas stations.
Good luck with your project.
Hi Plums,
I'm sorry but I don't do any work on any versions of the Jaguar V8 engines.
#39
12-15-2012, 02:06 AM
Senior Member
bronze coloured cans
My model XJR has a pair oxygen sensors up front
I wanted as long as possible pipes from the headers before we bridged it into 1 pipe then splitting it to make the back spit section even length
The cats are High flow metal substrate 200 cell cats just legal over here when you hold them up to the light you can almost see through them the 100 cell cats you could see more light
I wanted the car legal if possible
Last edited by doc; 12-15-2012 at 02:07 AM. Reason: typo
#40
12-15-2012, 10:42 AM
thank you
Hi Aldol,
XJRguy has already confirmed that X300s are OBDII compliant, albeit with a few bugs in the software. Incidentally, the airflow rate is measured in units of 0.1gm/sec.
I don't know of anyone other than me who replrogrammes ECUs for AJ16 engines, but then I would say that wouldn't I. Seriously, there isn't really enough demand for anyone to make a business out of modifiying these engines. If it wasn't for the fact that I wasn modifying my own cars I couldn't justify the time I have spent remapping the ECU.
As you have obviously spent quite a lot of time and effort on your XJ6 I assume that simply swapping it for an XJR6 is out of the question. However, a simpler solution than reprogramming your ECU would be to fit an ECU from an XJR6 along with the MAF and injectors, unless you think your centrifugal compressor is going to flow more that 1018kg/hr of airflow. Personally, I would be very cooncerned that your engine is going to be extremely knock limited if you retain the 10.0:1 compression ratio and fit a supercharger. The AJ16 supercharged engine has an 8.5:1 compression ratio and an ignition map to match. However, even if you use the ECU from an XJR6 with your modified engie, the ignition is likely to be far too advanced for the std AJ16SC ignition map. Your would certainly be testing the knock control system to the limit even if you ran it on the highest octane fuel that you can buy from gas stations.
Good luck with your project.
Hi Plums,
I'm sorry but I don't do any work on any versions of the Jaguar V8 engines.
XJRguy has already confirmed that X300s are OBDII compliant, albeit with a few bugs in the software. Incidentally, the airflow rate is measured in units of 0.1gm/sec.
I don't know of anyone other than me who replrogrammes ECUs for AJ16 engines, but then I would say that wouldn't I. Seriously, there isn't really enough demand for anyone to make a business out of modifiying these engines. If it wasn't for the fact that I wasn modifying my own cars I couldn't justify the time I have spent remapping the ECU.
As you have obviously spent quite a lot of time and effort on your XJ6 I assume that simply swapping it for an XJR6 is out of the question. However, a simpler solution than reprogramming your ECU would be to fit an ECU from an XJR6 along with the MAF and injectors, unless you think your centrifugal compressor is going to flow more that 1018kg/hr of airflow. Personally, I would be very cooncerned that your engine is going to be extremely knock limited if you retain the 10.0:1 compression ratio and fit a supercharger. The AJ16 supercharged engine has an 8.5:1 compression ratio and an ignition map to match. However, even if you use the ECU from an XJR6 with your modified engie, the ignition is likely to be far too advanced for the std AJ16SC ignition map. Your would certainly be testing the knock control system to the limit even if you ran it on the highest octane fuel that you can buy from gas stations.
Good luck with your project.
Hi Plums,
I'm sorry but I don't do any work on any versions of the Jaguar V8 engines.
I appreciate the info... really a big help already.
i will try to do just that , get an xrj6 ecu a MAF and injectors and try it.
in order to go back to what i have now , just in case it does not work i will keep the old ecu
any tips or caveats about the wiring of the xrj6 ecu?