That TSB is what I found after looking at that 2004 (US model year - that might be 2003 in Europe.) The one I drove kept doing it, even after it was plenty warm, 30 minutes or so. My test drive was some town, and a bit of 65 mph highway.

 

Hello Fraser. I just searched the ALLDATA and it did not list the TSB B307-04. It did list quite few. I see 307-01, 307-02, 307-06, 307-08.

Is there anyway to get the B307-04? thx!

 

That TSB B307-04 is interesting.
Ever since buying my 2003 X350 3.5L V8 in 2009 it has a slight hunting on warm up.
From cold at speeds about 50 to 60kmh after 1 minute it will have the effect for about 30 seconds then no prblem.
It happens in a very narrow band of the warm up cycle.

I thought it was just the base fuelling map having 2 or 3 cells so close toether that could be the cause.
One of my XJ-Ss has an aftermarket management system which I can tune, so I know about that problem.

 

It's printed out in the latest copy of the Jaguar Enthusiasts Club magazine. I'll see if I can post up a photo that is readable. The main point in it is that the dealer has to get a code off Jaguar to run a program, due to homologation issues; the program is not just removed as the emissions acheived by the car are part of the homologation in the country of use.

 

Hi Everyone.. Just a quick update

Gear fault error: Has not come back in 100+ miles of easy driving. Still not out of the woods but promising.

I decided to tackle the high LTFT. To refresh LT fuel trims are 6.25% at idle, 12.5% under light load/acceleration and 15% under heavier acceleration. I remove the MAF and the sensor elements were very dirty. I sprayed them thoroughly w/ MAF sensor cleaner and re-installed. The air cleaner housing assembly was a little tougher than I expected to line up. IT was like wrestling a baby alligator. Go for a ride the the trims got way way worse! at idle LTFT around 18 and w/ light throttle around 15-16. I even got a restricted performance error (P0171).
I decide to smoke test for leaks. I smoke it from the air cleaner intake opening. Wrap a thick towel around the smoker nozzle and opened the throttle.. I let it run for a while and only had two minor leaks from the two big clamps that attach the air cleaner tube and throttle body. Otherwise nothing. I checked everywhere. I opened the oil cap to be sure the smoke was working and there was smoke. I tightened the clamps and drove the car, but no change in trims.

Ordered a new Delphi MAF sensor and installed. Initially at idle the LTFT bank1 was 15 and LTFT bank2 13. After a 90 mile drive the trims went down to 10 / 8.5. Happier but I really want to see zero trims. I'm going to keep driving a bit more so see if they continue to drop. I keep having a feeing that air cleaner assembly is not on right. Am I missing anything?

Question to those w/ zero Long term trims.. On part and moderate throttle what do your LT trims go up to?

Otherwise the car ran absolutely perfect.

 

Hey I have been chasing a weird trans issue with JCalhoun, thread is here. I need to update but will summarize where I’m at here.

https://www.jaguarforums.com/forum/x...stions-238941/

I had zero trans codes, also had to drive like an egg was under my foot. Changed map sensor, throttle body/tps, finally coils and plugs.

Throttle body and map sensor didn’t seem to do anything. Coils made a difference at first, then I got restricted performance but no shifting issues. Reset codes, drove a few days with no issues, then back to harsh shifts, blowing in to neutral etc.

My dad insisted on resetting adaptations again. He did the driving portion 4-5 times. Then started accelerating harder and harder. Then went for the down shifts. All was well.

Now once in a while I get restricted performance when go for a down shift. It seems to happen at 3/4 or so throttle once it’s loaded up. No engine codes, just the P1643 and related cruise faults. I believe when it hits restricted performance various modules stop talking to each other.

To answer your questions about fuel trims, I logged mine and can can be seen here.


When they jump up briefly to 16% or so I am coasting. Hopefully others can comment on if they are normal, marginal etc.

 

Thanks Brad! Your fuel trims look excellent. I appreciate the time you took to record the video and post. I'm hoping mine will look like yours hopefully soon. Did you fuel trims look like this before you changed all those parts? Looks like you fixed your transmission issues. Nice job. After resetting the adaption did you follow the TSB... I did the gradual acceleration up to 50 mph (making sure all the shifts occurred between 1300-1800). Once I reached 50 mph I lightly braked and coasted to a stop. Did this 6 consecutive times. I've driven 300 miles and no issues, but driving the car very easy (no sudden burst of acceleration).

As for the LTFT they got a low was 7% LTFT1 and 6.25% LTFT2. they creeped up to 9 and 8.25 by the end of the day. Again on light throttle 11% and 13%. I changed the air filter for maintenance.
I need to keep researching areas to check. Maybe I didn't smoke correctly?, but the trims on increasing with increased throttle so I'm think maybe something other than vacuum leak? maybe.

 

Update: still no gearbox fault error and the LT Trims for both banks are 0% at idle. Still under load (light to moderate throttle) LT trims increase to 10-11%. I'm going to investigate a few things when I have time (possible leak at throttle blade pivot point, IAC.. trying to narrow if lack of fuel (fuel pressure a solid 55 so maybe not a fuel issue) or unmetered air.

I did have one bad hot start issue where the engine was stumbling very badly (felt like a stuck open EGR valve) fuel trims on Bank 1 were both 25% Short and Long term. Bank 2 were normal. I got a P0300 P0301 P0303 P0101 P0101. Otherwise engine still running perfect.

 

Here is the TSB about the surging.
I think it's S307-14 not 04?
.
.
.

 

That applies to the S-type, although the gearbox is the same in the 2003-on XJ saloon. Maybe the one I quoted was withdrawn and dealers told to reference this one. Anyway note the bold type warning about homologation

 

Thanks for the attachment containing the Technical Bulletin.

I recently recorded data during a WOT run to determine if there is an issue w/ the new MAF sensor I installed.
Based on the 80% rule(80% of peak engine HP), the MAF should be flowing 235 g/s (4.2L peak 294 hp) @ WOT. The data showed 177 g/s @ 5200rpm. I also calculated the Volumetric efficiency (I found a simple calculator online that calculated 75%; but went up to 100% when I plugged in the ideal 235 g/s).

My observation: 1) not a fuel issue.. Fuel pressures a steady 55 psi and increased under full throttle and downstream O2 sensor pegged to rich at WOT 2) MAF sensor is defect (even though new). I should of bought a OEM Denso. MAF sensor working but not perfectly. 3) I've heard a bad IAC valve could cause positive trims. 4) no unmetered air leaks. Trims perfect at idle and I also saw no leaks when I smoked the intake. Fuel trims increase under load only.

has anyone recorded their MAF g/s at WOT ?

 

Having owned an Audi A6 and now an A8 for over 15 years there are certain parts that must be OEM. MAF sensor being one of them. From my limited experience, Jaguar seems to be the same.

 

You're right. In hindsight I should of bought the Denso, but my cheap side wanted to save a few bucks.

I'd still love to know the value of a known good MAF g/s reading @ WOT. I know there is a great website iatn.net that contains a database of known good graphs, chart etc but I'm not a member.

 

Hello Everyone. Just wanted to give a quick update.

I never changed out the new Adelphi MAF sensor for a new Denso unit. The total fuel trims settled at 5%, so for now I decided to leave as is. I then installed BG44K fuel system cleaner to a fuel tank of gas and the car ran better and noticed that the surging/hunting reduced significantly. It now only does it very little during warm up (very livable) and fter warmup I barely notice it. Finally (don't want to jinx myself) the gearbox fault code never returned. I've driven the big cat over 1000 miles and rides perfect, even w/ the more peppy driving.

I've guess engine performance does really affect the TCM.

 

New XK8 owner here w/ a dumb question. Are all XK8's air shocks? Own a Lexus LS430. When the air shocks go it's coil over time. Minimal difference in comfort and a BIG difference in price.