Hi, does anybody know if the ecu restricts performance until the engine is up to temperature?

The reason I ask is because I purchased a 3.0 Diesle XF a few weeks ago, my first Jaguar, and It seems to rev a little slower until up to temperature. This seems to happen every time the car is left for a few hours or more. To be honest, I first noticed this after trying to accelerate at full throttle a few minutes after startup. I know accelerating hard on a cold engine is a cardinal sin, but It pulled more like my old Peugeot 406 than a 3 litre Jag. I've tested this a few times now, no lights are on the dash and theres no lumpiness but it definitely revs slower until up to temperature.

For piece of mind I've booked it into a Jaguar specialist to run a diagnostic but the earliest slot is next Tuesday, so until then if anybody has any simular experience or knows whether this is a feature please tell.

Thanks,

Andy

 

Doesn't sound right to me, I had no such problem on my old XFS. I generally did not boot it while it was cold, but after about 2 minutes it was perfectly OK to do so.
By "revs slower" do you mean it still kicks down to the correct lower gear but then takes ages to build revs, or do you mean it doesn't kick down properly?
One common complaint with the 3.0 D is a propensity to kick down one gear too many when you boot it, so that it revs it's **** off (which is only 5,000 RPM for a diesel anyway) for about a second before changing up to the next gear.
I recall reading somewhere that the Transmission Control Unit (TCU) restricts the kick down a bit while the gearbox is cold, and maybe that is what you are experiencing. And if so, maybe your TCU as playing up a little and being too much of a Nanny.

 

I think you might be onto something there! ... I tried to replicate the issue earlier today on two occasions but it seemed to behave itself. The only difference was that I put the transmission straight into manual. I think more testing is in order!