''Restricted Performance " driving me crazy!
#1
''Restricted Performance " driving me crazy!
Hi all,
My 4.0 liter X308 is in restricted performance mode. It will start and idle just fine. If you drive it easy it runs fine if you get on it, it falls flat on its face. I am trying hard to work on this myself as I currently have two with an XK8 coming soon. I digress I've checked the coil packs at idle all seem to be firing. I've changed plugs, installed a new knock sensor as the other ones wiring was brittle and fraying. What should I check next. There was a time the wife was running regular gas if that matters the tank has premium now. Any help is appreciated as Jag mechanics in my area are few.
Thanks
My 4.0 liter X308 is in restricted performance mode. It will start and idle just fine. If you drive it easy it runs fine if you get on it, it falls flat on its face. I am trying hard to work on this myself as I currently have two with an XK8 coming soon. I digress I've checked the coil packs at idle all seem to be firing. I've changed plugs, installed a new knock sensor as the other ones wiring was brittle and fraying. What should I check next. There was a time the wife was running regular gas if that matters the tank has premium now. Any help is appreciated as Jag mechanics in my area are few.
Thanks
#3
There are two knock sensors. This thread may be helpful.
https://www.jaguarforums.com/forum/x...t-1-2-a-76815/
https://www.jaguarforums.com/forum/x...t-1-2-a-76815/
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David Stevens (03-17-2017)
#4
#5
Both the same part number! In that thread someone suggested getting XK sensors, as they are cheaper and work just fine.
Engine Sensors-V8 - Parts For XJ Series from (V)812317 to (V)F59525 (X308) | Jaguar Classic Parts UK
Engine Sensors-V8 - Parts For XJ Series from (V)812317 to (V)F59525 (X308) | Jaguar Classic Parts UK
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David Stevens (03-17-2017)
#7
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#8
I thought they should ohm out at that. Guide me here please my code said bank 1 which I'm assuming is passenger side. I set my meter to 2000 ohm when I tested it read OL. I immediately removed it and when out the harness was brittle breaking rubber piping off. The new one arrived today it read the same OL what am I doing wrong. After learning of the second I tested it reading the same, removed it to see bare wire going to it so I ordered another. Why am I not getting a reading when I ohm it.
Thanks
Thanks
#9
You're on the 2,000 ohm scale. The brand new knock sensor should read 202,000 ohms of resistance. I have to set mine to 2,000,000 (or 2 million) ohms to test that circuit without the possibility of being over my scale and giving me false readings.
Last edited by Addicted2boost; 03-18-2017 at 05:58 AM.
#10
#11
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David Stevens (03-18-2017)
#12
#13
David, the ELM 327 seems to work, a number of forum members use them, some have bluetooth/wifi and are used alongside apps and programs on phone/tablet/pc. Have a look at Torque Pro if you want to go that route.
Readers with screens are cheap enough now - you don't need a Snap On cirrus, something like the Memoscan U581 I've been using for years on various Jags and it works a treat for pulling/clearing engine codes quickly.
Readers with screens are cheap enough now - you don't need a Snap On cirrus, something like the Memoscan U581 I've been using for years on various Jags and it works a treat for pulling/clearing engine codes quickly.
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David Stevens (03-18-2017)
#14
#16
I had a similar problem, ran fine around town, go to the highway and get about 60 and it would flatten out, and sputter. also got the reduced performance light. hooked my reader up and (do not remember the code off hand) the code was for a gross air leak in the EVAP.
My first go to was the purge valve under the hood/bonnet on the bulkhead, come to find out, somehow it came unplugged, but also had a hose slip off one to the connections. looked like someone had changed it before and did not use enough length of hose and had it held on with spring clamps luckily I still had some silicon vacuum hose left over from when I did my XJS. cleared the code and all is well.
My first go to was the purge valve under the hood/bonnet on the bulkhead, come to find out, somehow it came unplugged, but also had a hose slip off one to the connections. looked like someone had changed it before and did not use enough length of hose and had it held on with spring clamps luckily I still had some silicon vacuum hose left over from when I did my XJS. cleared the code and all is well.
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David Stevens (03-20-2017)
#18
#19
Fixed
Sorry I've been in training all week. The knock sensor fixed the problem. I purchased a tool so I can clear codes so that's do. If you read the thread you undoubtedly seen where the coolant recycle tube was brittle and broke in two places when snapping it back in the engine cover. Awaiting the part now. A big thanks to all who add their thoughts and expertise. I'll slowly figure out how to work on these.
Again thanks all
Again thanks all