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Have you had a look what that hose is attached to, removing the TB is 4 bolts and pulling the TB to see what you've got?
Yeah, so I did that last night and, well, nevermind.
I bench tested the TPS and it seemed fine - smooth progression on both tracks from stop to max. I reinstalled it using 4 M4x16 allen head screws with some split washers. That's how Volvo does it, so that's how the Jag is now too. 16mm is slightly too long, 14mm would be great, but I didn't have and couldn't find those. The extra length does not appear to be a problem.
I was able to get Track 2 into X-Type spec but Track 1 would not - at *full* adjustment Track 1 was at .4 k ohms, and that pushed Track 2 to 1.6 k ohms. No further adjustment was possible, and even if it was it would have moved Track 2 well past spec.
Car started readily but set into a 900rpm idle. It was pretty cold out, so a somewhat high idle was expected - I don't know about 900rpm though. I let it sit for a while, and could hear the TB clicking every so often. Not sure what that indicated. I turned the cable actuator assembly, engine revved, went back to 900rpm. As I was walking around the other side of the car I noticed FAILSAFE OPERATION on the dash so I shut it down.
I'm headed out of town for a few days, but I think the next step is to swap the other throttle body on. Seems like Track 1 on the current TPS is hosed. I considered swapping TPS (though I'm loathe to mess up a TB that's known working) but the clicking from the installed TB gives me pause - I don't know whether that means the gearbox is trashed or whether it's a side effect of the goofy TPS. I just really don't want to mess with something that should work for something that might work.
There are several XJs in local junkyards, so I may also harvest some test parts... Always nice to have a selection of crap to mess with. In any case, this project will be on hold for a week, but I'll come back with whatever I learn.
Last edited by thesameguy; 03-23-2017 at 01:48 PM.
Did you hard reset before fitting the other TB, the car will still be in limp mode from the other TB fault. 900 can be adjusted out, and it's a rare thing to break the R trans.
I'd like to know what you found, well never mind isn't good enough! lol - good luck with it
The car was not in limp home mode to start - the key cycle on the way home had restored regular operation, with no warning lights or messages. When I started the car last night, still no warnings or messages. It was only after revving the engine that RESTRICTED PERFORMANCE returned. Also, the TPS was turned fully clockwise (when facing it) - it could not turn any further.
I will try a hard reset just to be sure and I'll hook up the Autel to watch the pedal & throttle position tracks electronically before taking anything apart. It's gonna kill me to be 800 miles away an unable to experiment for a few days (I might be mildly OCD ) but I'm leaving in an hour!
While I'm gone, I can try and find a base gasket for a replacement TB. I'm finding conflicting information on whether NNE3021AC is correct or not.
I played with the TPS on the original TB for a little while longer, but could not get Track 1 into the spec listed in that X-Type TSB I posted earlier. I realize, of course, there is no guarantee the X-Type and XJ share the same specs, but there is a fair amount of anecdotal evidence that suggests they do... including the fact the spare TB I have is fully original (still has the white paint) and square within those specs. I was able to get my existing TPS close, but never within spec and the car *clearly* didn't like it... it would start and idle fine, but at some point in throttle pedal travel the FAILSAFE message would return along with the P1229.
So, over the weekend I replaced my TB with the spare I had. As you mentioned, Sean, I needed to replace the little cover on the back, being careful of the formed seal inside. While I was in there, I bypassed the throttle body coolant feed - it's just 3/8" hose on both sides so I looped it back to itself. I'm not worried about my throttle body freezing in California on a supercharged car, and maybe less heat on the metal will prolong TB life. Who knows?
I put it back together, adjusted the throttle cable, and took it out on the road. I did NOT hard reset it. I only have 10 miles on it this morning, but all seems well. Once warmed up idle stabilized at 600rpm, throttle response is perfect, and my slightly unstable idle is gone. At this moment it's better than it's been in two years. Nice to know that XJ TBs are interchangeable with just a minor part adjustment.
On a side note, Pick & Pull had their half off sale last weekend, and while searching for parts for a fuel injection swap on a Saab I also checked out the few XJs laying around, hoping to find a spare TB to experiment with. No such luck, all were long gone. I guess someone is methodically harvesting them... probably as rebuilder cores or ebay fodder. I'll probably keep my eyes open - I'd like to have another sample.
I'll report back if any problems with this TB present, but if you don't hear from me it's because all is well.
I have made a few post about my throttle body and the car is now running really well after taking members advice.
However the other day I heard a clicking sound that appears to be coming from the left hand side of the Throttle Body as you look at it from the drivers front wing.
Have checked the connections and any cables to ensure they are not causing the fault.
When does this clicking sound happen? Engine on or off? The throttle body does make clicking sounds on ignition switch on and engine shut down, it’s part of its operation. But if it’s doing whilst running that may be a different matter all together.
The AJ27 (1999 on) has a fly-by-wire throttle body that parks on ignition on & off, which makes a clicking sound - usually 2 clicks then a delay and a final click. This is normal operation. Like Stu suggests, if it's doing this while running it will post a code and will definitely go into limp mode.
The codes should be P1121/P1122. It's either a bad connection to either the pedal position sensor or throttle position sensor, Jaguar addressed this with a gold pin connector kit and a recall, or, once over 100,000 it's usually one of the sensors.
What advice did you take and on what issue - and, did the TB make the clicking sounds before you addressed it? Just trying to establish a fault timeline.
I replaced the throttle body with a used one from ebay. In the UK its difficult to get a company to recondition one. It did not initially make a clicking sound when I first installed it about three months ago. It only started last week. When its on idle and running. Have read about replacing the gold pin connectors and that was meant to be my next step.
There are no Fault Codes now, previously prior to replacing the TB code P1121 came up but since I replaced the TB all good apart from the obvious clicking.
Again thanks for the input and any advice much appreciated.
When I was driving I could hear a knocking sound that appeared to be coming from the back of the engine by the TB.
When I rev up and release the revs I hear the knocking sound but not when I accelerate. Am going on a journey London - Cardiff and will report back if it changes.
What would be helpful, if you can manage it since you say it happens whilst driving (I know England frowns heavily on phones and such driving)...is to get us an audio or video of it.
I finally found out that the clicking came from the Heat Shield on top of the exhaustbox. It was loose and just tapping on the exhaust, removed it and clicking gone.
However, yesterday it went into Engine Fail Safe Mode, Stability & Traction , red & orange light but this time I had to wait 15 minutes by the side of the road. When I plugged in the diagnostic it came up with P1229, the engine safe mode could not be cleared by the OEBD. I had to remove the key and it eventually cleared it. This however worries me as I am not addressing the problem and it will happen again.
Also the accelerator revs high when I put it in D, it revs at 10,000 instead of 6,5-7,5 rpm. When I then put it in N it eventually goes back to normal idle. I have checked the cable and it seems ok but would appreciate any advice, as taking to a garage will only plug in diagnostic and tell me what I already know.
To summarise:-
1 - Fault P1229 - When in Engine Fail Safe Mode ( New one on me as the previous faults P0121)
2 - Knocking sound when I rev the accelerator and release, on the release I hear the sound.
3 - Engine revs high when in D and take time to come back to normal revs.
Any help would be much appreciated as I am planning a long journey next week. PLEASE..........
I have previously posted about my Throttle Body and replaced the part with one from ebay (UK) as its difficult to get refurb in UK.
Yesterday it went into Engine Fail Safe Mode, Stability & Traction , red & orange light but this time I had to wait 15 minutes by the side of the road. When I plugged in the diagnostic it came up with P1229, the engine safe mode could not be cleared by the OBD II. I had to remove the key and it eventually cleared it. This however worries me as I am not addressing the problem and it will happen again.
Also the accelerator revs high when I put it in D, it revs at 10 instead of 6,5-7,5 rpm. When I then put it in N it eventually goes back to normal idle. I have checked the cable and it seems ok but would appreciate any advice, as taking to a garage will only plug in diagnostic and tell me what I already know.
To summarise:-
1 - Fault P1229 - When in Engine Fail Safe Mode ( New one on me as the previous faults P0121)
2 - Knocking sound when I rev the accelerator and release, on the release I hear the sound.
3 - Engine revs high when in D and take time to come back to normal revs.
Any help would be much appreciated as I am planning a long journey next week. PLEASE..........
I'd be sure to replace that heat shield, it does serve a purpose. Its not fun to put back, see my write up in the How To on O2 sensor replacement.
I hope your revs were at 1000, not 10,000....that's F1 and NASCAR turf motors...
Here's a thread on the 1229 for review... https://www.jaguarforums.com/forum/x...29-lol-178564/ ...and may be your rev issue also.
Where is the knocking coming from? Front/back of the motor? Cam cover/oil pan?
I have merged the new thread you started with this one and re-titled the merged thread to reflect the current status of your Jaguar. Please do not start any additional threads on the same subject; having all the information and replies in one thread helps avoid confusion and duplicate effort on the part of other members who want to help.
Regarding P1229, here are the definition and possible causes from the Diagnostic Trouble Codes Summaries:
I am attaching the P1229 Pinpoint tests from the Workshop Manual, which give you several electrical tests you can conduct to identify the cause of your DTC and Failsafe Mode. The easiest test is for the Throttle Body relay constant supply (the second item in the pinpoint tests), so that's what I would check first.
03-23-2017, 09:28 AM
16mm is slightly too long, 14mm would be great, but I didn't have and couldn't find those. The extra length does not appear to be a problem.
