New member with 54reg 2.0l d sport

[big mark]

Just thought I would say hello to all, first time jag owner. very happy with my car.

there is one question, when cruising it gets a bit jerky? any ideas. 

[msmicksmith]

Welcome to the forum.

Any more detail you can add to your cruising problem? Lots of people on here who will help if they can

[big mark]

ok thanks mick.

 

when I am doing 50mph the cars acceleration seems abit jerky, sort of holding back a little? but as soon as you accelerate its fine.

[msmicksmith]

Sadly, there are a lot of things that can cause that.

It will be a case of a process of elimination but start with the easiest first. Usually, these type of faults are caused by something simple.

In a diesel there's not much in the way of 'simple' to check. Injectors are a common problem and usually it's because of dirt around the nozzle. I use Millers Diesel Eco-Power additive to clean mine as its easy and effective.

Finding these faults isn't easy as they don't show a fault in the ecu and no fault codes are stored. All you can do is cover the basics then start the process of replacing possible suspect parts.

One part which can cause running faults but often isn't detected as faulty by the ecu is the Air Mass Meter. You can try removing it and cleaning it with carb cleaner. DON'T touch the sensor with anything. They are extremely sensitive. The best I'd suggest is a rolled up piece of kitchen roll to gently rub the surface with but nothing more. Unfortunately if it's faulty the cleaning won't fix it and you'll not know unless you renew it. They aren't horrendously priced though. EGR operation on yours is vacuum operated I think. Check the vacuum hose isn't split or that further up its supply line isn't damaged. A loss of vacuum will cause the EGR to not fully operate.

Get the basics covered first though. Injector and fuel delivery system cleanup with Millers. Remove and clean the EGR valve. The cleaner burn from using Millers will ensure its stays clean afterwards.

Replace the air filter. Genuine Jaguar is only 15 quid.

Once you have the basics sorted you can then start the less easy stuff but you may find you cure the problem beforehand

[big mark]

thanks mick I will do all that, I will repost if any of them cure it. cheers