The topic "Delay" when accelerating from stop, was started on the XE page, June 2019. There was some good input but I’m having the same problem with my 2017 XJ. I didn’t see that there had been a solution, albeit, several interesting suggestions. I’m copying my post to the XJ forum in the hope that someone may have had some success correcting the problem with their XJ. (No, I’m not wanting anyone to have problems, just looking for solutions.)

I’ll try to make this short. There’s been input but no solution from the service department that I use. problem, but no solution from the Service Department. There is a slight, but noticeable, hesitation when accelerating from a stop. It’s not unlike a fore and/or aft driveshaft movement.

The vehicle is a recently acquired CPO, 2017 XJL Portfolio, SC V-6, with 2 years remaining on the original warranty and an additional 2 years on the CPO.Early this month (July 2020), I took it to the dealer with a few things needing attention and the “delay” issue was paramount. The technician checked the codes and determined that it needed a software update of the PCM/TCM. After which a diagnostic test showed no faults. He also checked the drive train to be sure there was no mechanical issues.
Problem was, it still wasn’t fixed! I returned the vehicle back to the dealer the following week. Took a test drive with the technician, got some agreement that the delay and noise was still prevalent, but he didn’t have an answer. After some discussion about various possibilities, I agreed to take the car back, to see if the software update might eventually solve itself, by “learning” the driving pattern. We had a Lincoln MKX that would adjust gear changes based on whomever was driving; so, I agreed to give it a try. As of now, no improvement.

Obviously, I’m looking for anyone who’d experienced this problem and had it successfully repaired.
THANX, in advance.

 

So is the delay from stop/start and the engine restarts when you are ready to accelerate. I ask because I had this issue and changing the tensioners and guides eliminated the issue.

 

I may be wrong, but I haven’t heard of the chains/ tensioners being an issue on any V6 engine or on MY2015 and after.

Have you recently replaced your air intake filters? I change mine every 6-12 months.

 

KingFala, has anyone cleaned your throttlebody recently? Most likely they haven't. You can take a rag with a bit of cleaner and open the butterfly valve and wipe away the brown varnish that has built up there. Wipe until the whole surface is clean (shiny silver). After that, look at the edge of the silver disc and clean that too. Clean both sides (reaching in is a bit of a pita, but needs to be done). I would finish it off with spraying a little bit of the cleaner (I tend to use throttlebody cleaner) near where the shaft runs on each side to get any gunk that has built up there that you can't reach with your finger. See what you have then.

 

I never use the start/stop function. I abhor the concept and dislike the police state telling me what to do. Actually, to determine the depth of the problem, I have experienced the problem with or without the "stop/start" feature, and it's the same.

I will do the throttle body cleansing recommended to see of that fixes the issue.

I appreciate all of the input and will try whatever is necessary to be able to get a smooth get away. Someone on the XE site mentioned that the Land Rover / Range Rover vehicles were having similar problems. One would expect that the info would be available to the Jaguar side of the corporation. I'll mention it to the service department the next time I make an appointment.

 

After weeks and months of diagnostics, trying this and that, discussions with Jaguar engineering, many, many test drives, looks like something that can't be fixed or .... somebody doesn't or can't do it! Looks like it's new transmission time. Stay tuned!

 

If I remember correctly, I've seen a few threads about this on the F-Type forum. Here is one below that involves the V6.
I can't find the other ones but they basically had it resolved by having their tuner fix it in the tune.
Post #22 says they all do it and
#24 says it happens even w/their manual vehicle.
https://www.jaguarforums.com/forum/f...le-tip-140537/

 

Found one of them at least.
https://www.jaguarforums.com/forum/f...6/#post1560361

Post #312:
Nothing but commuting since the tune, but I do have a few impressions now. No dyno readings, no lap times, no ETs. I'll need to fill up tomorrow, so will have a first fuel economy reading then.

The purely subjective short term report:

- stronger midrange
- revs more quickly
- pulls more cleanly to redline
- increased sensitivity/response in first 1/4 of pedal travel
- previous lag between pressing accelerator and engine response is greatly reduced

That last one needs a little more explanation. I've mentioned it before, but there is an inherent lag in the system. Perhaps it's more noticeable on the manual transmission, but the feeling I've had is that the engine delivers power mildly until it passes a threshold, then goes to more aggressive acceleration. That threshold seems to be a combination of pedal position and RPM, and the transition is as noticeable a the change when turbocharged engine "spools up." I still feel the transition, but it comes sooner (lower RPM and less throttle) so is not as abrupt. I don't feel like I need to gas it to get past the transition, then back off to the power I really want.

Surprisingly, at light cruise it seems smoother too.

Post #316:
Just installed the Stage 1 Tune for my MY16 AWD R. Will be doing the Stage 2 once I get the Pulley installed next week. Initial impressions.

- The midrange has come alive
- A slight increase in gas mileage
- Exhaust: The exhaust pops and crackles are more tame now, before I could have the car in 2 gear and accelerator to 3000RPM, let off and the fireworks would go off, with the Stage 1 tune this doesn't happen as easily if at all. I still get the farting in 1st gear, I'll have to play with this more tomorrow. On the other side, the note feels a bit more deeper/throaty now.
- The acceleration is ALOT smoother than stock tune. The car pulls like butter, especially when in dynamic
- The cars revs a lot quicker
- The pedal lag is gone, when you tap the pedal now there is an instant response from the car, and getting to speed feels effortless. (Something you need climbing San Francisco hills)

Overall, I am quite pleased with the results thus far. I will have to play around with the exhaust sounds tomorrow, to confirm that I have lost some of the crackle & pops from the tune.