Gearbox light, idle problems
#1
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Hello all,
I have learned a lot of things about Jaguar XJ6 problems here, but now, I have to post something that I cannot confirm what it is.
I had changed the pump-to-engine water hose. I removed the supercharger to do that... I had to unplug the TPS and now I think that it needs to be updated because it’s generating my gearbox problem. The idle is not stable it sometimes at 1500 rpms to 2000 rpms, but never under the 1000 rpms.
Could be the TPS the problem of this mess?
Symptoms that are present on the car:
Fluctuating revs.
Light gearbox warning light on the dashboard.
Not smooth shift.
180.000kms showed on the dashboard.
No OBDii code.
CAR information details:
XJR X300 automatic transmission
MY1994 November
180.000kms
thanks in advance
kind regards to all readers
I have learned a lot of things about Jaguar XJ6 problems here, but now, I have to post something that I cannot confirm what it is.
I had changed the pump-to-engine water hose. I removed the supercharger to do that... I had to unplug the TPS and now I think that it needs to be updated because it’s generating my gearbox problem. The idle is not stable it sometimes at 1500 rpms to 2000 rpms, but never under the 1000 rpms.
Could be the TPS the problem of this mess?
Symptoms that are present on the car:
Fluctuating revs.
Light gearbox warning light on the dashboard.
Not smooth shift.
180.000kms showed on the dashboard.
No OBDii code.
CAR information details:
XJR X300 automatic transmission
MY1994 November
180.000kms
thanks in advance
kind regards to all readers
#2
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Alejandro_Montijo (05-10-2021)
#3
The following 2 users liked this post by Vee:
Alejandro_Montijo (05-10-2021),
Don B (05-12-2021)
#4
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Do you known how can I do that? could you please subject a software to connect the car to the computer?
kind regards Vee
#5
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With the supercharged engine you have the different GM transmission then the rest of the non - supercharged ZF transmission
There are a couple of Jaguar TSB's with the GM transmission you may want to review
JagRepair.com - Jaguar Repair Information Resource![Icon Dance Disco](https://www.jaguarforums.com/forum/images/smilies/icon_dance-disco.gif)
One that comes to mind is if you have the orange dot or not
In removing the supercharger you may have left off the inlet air temp sensor connector and your TPS could be just fine
The engine ECU and the transmission ECU must talk to each other to coordinate their activities around the areas of throttle kick down and idle position expecting a 1st gear selection
The later X308 with the V8 has 2 separate TPS's one dedicated to each ECU where the X300 must share the one TPS
There are a couple of Jaguar TSB's with the GM transmission you may want to review
JagRepair.com - Jaguar Repair Information Resource
![Icon Dance Disco](https://www.jaguarforums.com/forum/images/smilies/icon_dance-disco.gif)
One that comes to mind is if you have the orange dot or not
In removing the supercharger you may have left off the inlet air temp sensor connector and your TPS could be just fine
The engine ECU and the transmission ECU must talk to each other to coordinate their activities around the areas of throttle kick down and idle position expecting a 1st gear selection
The later X308 with the V8 has 2 separate TPS's one dedicated to each ECU where the X300 must share the one TPS
Last edited by Parker 2; 05-12-2021 at 07:55 AM.
#6
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Unfortunately, it is not possible to simply hook up a laptop to the car, you will need some special hardware/cables to connect to the cars OBD2 port. No way to make one at home.
Since you have a supercharger, there won’t be any way for you to even attempt to adjust the TPS manually, as you’d have to do this, in the blind, by feel, with the engine running. You would have to loosen the two bolts holding the TPS in place, adjust the position while engine is running, and then be able to tighten in place.
Last edited by Vee; 05-12-2021 at 08:02 AM.
The following users liked this post:
Don B (05-12-2021)
#7
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You would have to own a WDS, PDU or an expensive dealer level device, or a VCM-2, or a Mongoose. The clone devices may work, but not for long, so try to stay away from those.
Unfortunately, it is not possible to simply hook up a laptop to the car, you will need some special hardware/cables to connect to the cars OBD2 port. No way to make one at home.
Since you have a supercharger, there won’t be any way for you to even attempt to adjust the TPS manually, as you’d have to do this, in the blind, by feel, with the engine running. You would have to loosen the two bolts holding the TPS in place, adjust the position while engine is running, and then be able to tighten in place.
Unfortunately, it is not possible to simply hook up a laptop to the car, you will need some special hardware/cables to connect to the cars OBD2 port. No way to make one at home.
Since you have a supercharger, there won’t be any way for you to even attempt to adjust the TPS manually, as you’d have to do this, in the blind, by feel, with the engine running. You would have to loosen the two bolts holding the TPS in place, adjust the position while engine is running, and then be able to tighten in place.
That is the problem. On supercharger engine, the throttle body is not properly designed :$ to do this job. Any way I will have to pay the Jaguar shop to do this.
Tanks you so much.
I will post when I finally have the solution and the price for this kind of job in Spain
kind regards Vee
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#8
#9
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There is a throttle body return spring TSB X that they may not be accounting for
See page 11 , note that it mentions only non - supercharged engines
http://www.jagrepair.com/images/TSB/...all%20R493.pdf![Icon Dance Disco](https://www.jaguarforums.com/forum/images/smilies/icon_dance-disco.gif)
The previous owner may have addressed the return spring by preloading it with a different attach point as you wind it ( This instead of a stonger revised return spring )
That could explain the butterfly not returning to the idle closed position and proper idle speed
See page 11 , note that it mentions only non - supercharged engines
http://www.jagrepair.com/images/TSB/...all%20R493.pdf
![Icon Dance Disco](https://www.jaguarforums.com/forum/images/smilies/icon_dance-disco.gif)
The previous owner may have addressed the return spring by preloading it with a different attach point as you wind it ( This instead of a stonger revised return spring )
That could explain the butterfly not returning to the idle closed position and proper idle speed
Last edited by Parker 2; 05-12-2021 at 08:52 AM.
#10
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Your throttle body butterfly may need to be cleaned as well. Having gunk collect on the butterfly on, at least, the non-supercharged version of this engine is common, and does cause these issues.
On the non-supercharged engine, cleaning the butterfly is an easy task.
Your work seems to have shifted something there. A vacuum leak could also create this problem. Please make sure you have no gaps where unmetered air can enter the throttle. People report success using propane around the intake to see if the engine idle changes….if it does, you have a leak.
Before taking it to the dealer, you may want to go back and double check your work.
On the non-supercharged engine, cleaning the butterfly is an easy task.
Your work seems to have shifted something there. A vacuum leak could also create this problem. Please make sure you have no gaps where unmetered air can enter the throttle. People report success using propane around the intake to see if the engine idle changes….if it does, you have a leak.
Before taking it to the dealer, you may want to go back and double check your work.
Last edited by Vee; 05-12-2021 at 09:08 AM.
#11
![Default](/forum/images/icons/icon1.gif)
There is a throttle body return spring TSB X that they may not be accounting for
See page 11 , note that it mentions only non - supercharged engines
http://www.jagrepair.com/images/TSB/...all%20R493.pdf![Icon Dance Disco](https://www.jaguarforums.com/forum/images/smilies/icon_dance-disco.gif)
The previous owner may have addressed the return spring by preloading it with a different attach point as you wind it ( This instead of a stonger revised return spring )
That could explain the butterfly not returning to the idle closed position and proper idle speed
See page 11 , note that it mentions only non - supercharged engines
http://www.jagrepair.com/images/TSB/...all%20R493.pdf
![Icon Dance Disco](https://www.jaguarforums.com/forum/images/smilies/icon_dance-disco.gif)
The previous owner may have addressed the return spring by preloading it with a different attach point as you wind it ( This instead of a stonger revised return spring )
That could explain the butterfly not returning to the idle closed position and proper idle speed
I tried to close the butterfly manually and it was not possible it was on its position. I do that because I rode here the problem with the spring that you mention but the butterfly doesn’t moved. Other think that I tried was to lose tension on the throttle cable in order to give more freedom to move but it wasn’t worked. That is the reason to make me think in a sensor problem. I also tried to release and check the IAC sensor and the measure of resistances was fine too…
Other question, the TPS failure is represent on the dash? It is, what is the light or warning code of this?
#12
![Default](/forum/images/icons/icon1.gif)
Your throttle body butterfly may need to be cleaned as well. Having gunk collect on the butterfly on, at least, the non-supercharged version of this engine is common, and does cause these issues.
On the non-supercharged engine, cleaning the butterfly is an easy task.
Your work seems to have shifted something there. A vacuum leak could also create this problem. Please make sure you have no gaps where unmetered air can enter the throttle. People report success using propane around the intake to see if the engine idle changes….if it does, you have a leak.
Before taking it to the dealer, you may want to go back and double check your work.
On the non-supercharged engine, cleaning the butterfly is an easy task.
Your work seems to have shifted something there. A vacuum leak could also create this problem. Please make sure you have no gaps where unmetered air can enter the throttle. People report success using propane around the intake to see if the engine idle changes….if it does, you have a leak.
Before taking it to the dealer, you may want to go back and double check your work.
This is possible to happen. A little hole on the intake could false the MAF sensor value but I don’t think used propone on the engine bay help me to find the problem. I have a tool to read the vacuum force but on supercharger engine it is difficult to find a properly place to take a measure.
#13
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See page 111 for a 94 / 95
Beginning with PO122
http://www.jagrepair.com/images/Trai...20-%202000.pdf
Beginning with PO122
http://www.jagrepair.com/images/Trai...20-%202000.pdf
![Icon Dance Disco](https://www.jaguarforums.com/forum/images/smilies/icon_dance-disco.gif)
Last edited by Parker 2; 05-12-2021 at 10:41 AM.
#14
![Default](/forum/images/icons/icon1.gif)
See page 111 for a 94 / 95
Beginning with PO122
http://www.jagrepair.com/images/Trai...20-%202000.pdf![Icon Dance Disco](https://www.jaguarforums.com/forum/images/smilies/icon_dance-disco.gif)
Beginning with PO122
http://www.jagrepair.com/images/Trai...20-%202000.pdf
![Icon Dance Disco](https://www.jaguarforums.com/forum/images/smilies/icon_dance-disco.gif)
#15
![Default](/forum/images/icons/icon1.gif)
We need to get to the bottom of your transmission light. I don't think that you can get that read very easily. I just reread your post and you have a 1994MY, so no OBD2. Other than a PDU, I'm not sure what you need to get your code read!
I would heavily recommend taking another look at how you reassembled the car after your repair, and pay very close attention to the TPS. Make sure it is installed correctly, without any loose connections. Also check for possible vacuum leaks. Something happened when you unplugged, then replugged the TPS. I am not confident your Jaguar Dealer can address this for you, unless they have the old equipment. I would definitely call them first.
In the meantime, if you're up for it, get back in there and re-inspect that TPS.
I would heavily recommend taking another look at how you reassembled the car after your repair, and pay very close attention to the TPS. Make sure it is installed correctly, without any loose connections. Also check for possible vacuum leaks. Something happened when you unplugged, then replugged the TPS. I am not confident your Jaguar Dealer can address this for you, unless they have the old equipment. I would definitely call them first.
In the meantime, if you're up for it, get back in there and re-inspect that TPS.
#16
![Default](/forum/images/icons/icon1.gif)
We need to get to the bottom of your transmission light. I don't think that you can get that read very easily. I just reread your post and you have a 1994MY, so no OBD2. Other than a PDU, I'm not sure what you need to get your code read!
I would heavily recommend taking another look at how you reassembled the car after your repair, and pay very close attention to the TPS. Make sure it is installed correctly, without any loose connections. Also check for possible vacuum leaks. Something happened when you unplugged, then replugged the TPS. I am not confident your Jaguar Dealer can address this for you, unless they have the old equipment. I would definitely call them first.
In the meantime, if you're up for it, get back in there and re-inspect that TPS.
I would heavily recommend taking another look at how you reassembled the car after your repair, and pay very close attention to the TPS. Make sure it is installed correctly, without any loose connections. Also check for possible vacuum leaks. Something happened when you unplugged, then replugged the TPS. I am not confident your Jaguar Dealer can address this for you, unless they have the old equipment. I would definitely call them first.
In the meantime, if you're up for it, get back in there and re-inspect that TPS.
Other information that I would like to share it that the car is 1994 November, I could say that it was one of the first which arrived to Spain. So maybe it has a software and hardware from model year 1995. I rode the MAF and oxygen sensors measure with the OBD so I am not sure to confirm which OBD the car has.
#17
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If you read the MAF and Oxygen Sensors with an OBD port, there is a very good chance that you should be able to read the TPS too! What did you use to read the oxygen and MAF sensors?
I use a wireless ELM27 dongle that can be bought very cheaply on eBay or Amazon. Just make sure you buy the WiFi one if you use iPhone. If you use an Android phone, you can buy the Bluetooth one. Then you just buy an app for the phone!! The app should be able to tell you what percentage open the TPS is. At idle it should read at about 12.9%.
I use a wireless ELM27 dongle that can be bought very cheaply on eBay or Amazon. Just make sure you buy the WiFi one if you use iPhone. If you use an Android phone, you can buy the Bluetooth one. Then you just buy an app for the phone!! The app should be able to tell you what percentage open the TPS is. At idle it should read at about 12.9%.
The following users liked this post:
Alejandro_Montijo (05-13-2021)
#18
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Look under the intake manifold for loose vacuum lines as one of mine was missing
I also found the TPS connector was missing the metal bar locking clip , you can find a replacement from one of the trunk dome lights
You will see 2 coolant fluid lines to heat the throttle body butterfly throat
See page 60 of the OBD 2 PDF as there are 2 versions of fuel and vacuum line hookups , 1 or 2 vapor canisters versions . A 2 canister system will have a square canister on each side of the car just fwd of the rear wheels . A 1 canister will only have one on the left side
I also found the TPS connector was missing the metal bar locking clip , you can find a replacement from one of the trunk dome lights
You will see 2 coolant fluid lines to heat the throttle body butterfly throat
See page 60 of the OBD 2 PDF as there are 2 versions of fuel and vacuum line hookups , 1 or 2 vapor canisters versions . A 2 canister system will have a square canister on each side of the car just fwd of the rear wheels . A 1 canister will only have one on the left side
Last edited by Parker 2; 05-13-2021 at 06:43 AM.
The following users liked this post:
Alejandro_Montijo (05-13-2021)
#19
![Default](/forum/images/icons/icon1.gif)
If you read the MAF and Oxygen Sensors with an OBD port, there is a very good chance that you should be able to read the TPS too! What did you use to read the oxygen and MAF sensors?
I use a wireless ELM27 dongle that can be bought very cheaply on eBay or Amazon. Just make sure you buy the WiFi one if you use iPhone. If you use an Android phone, you can buy the Bluetooth one. Then you just buy an app for the phone!! The app should be able to tell you what percentage open the TPS is. At idle it should read at about 12.9%.
I use a wireless ELM27 dongle that can be bought very cheaply on eBay or Amazon. Just make sure you buy the WiFi one if you use iPhone. If you use an Android phone, you can buy the Bluetooth one. Then you just buy an app for the phone!! The app should be able to tell you what percentage open the TPS is. At idle it should read at about 12.9%.
Thank for you advice.
#20
![Default](/forum/images/icons/icon1.gif)
Look under the intake manifold for loose vacuum lines as one of mine was missing
I also found the TPS connector was missing the metal bar locking clip , you can find a replacement from one of the trunk dome lights
You will see 2 coolant fluid lines to heat the throttle body butterfly throat
See page 60 of the OBD 2 PDF as there are 2 versions of fuel and vacuum line hookups , 1 or 2 vapor canisters versions . A 2 canister system will have a square canister on each side of the car just fwd of the rear wheels . A 1 canister will only have one on the left side
I also found the TPS connector was missing the metal bar locking clip , you can find a replacement from one of the trunk dome lights
You will see 2 coolant fluid lines to heat the throttle body butterfly throat
See page 60 of the OBD 2 PDF as there are 2 versions of fuel and vacuum line hookups , 1 or 2 vapor canisters versions . A 2 canister system will have a square canister on each side of the car just fwd of the rear wheels . A 1 canister will only have one on the left side