Jaguar S-type misfiring - Ron S
I have been running my July 1999 Jaguar S-type 3 litre SE auto since Nov 2001, averaging under 5000 miles p.a. Most mileage is local urban driving but about once a month I have a journey in excess of 50 miles. I then find at steady speeds of 40 mph and above that the engine appears to hesitate or misfire when I begin to accelerate. After about 100 miles or so the misfiring becomes less and eventually stops. The fuel used is Esso 95 regular.

Is my problem due to the urban driving causing a 'coking up' or does it indicate a more serious problem?
Jaguar S-type misfiring - Ben79
Long long is your average journey? Has the car been serviced recently? Could you have damp in the ignition system?

When you have driven it for a long way, how long does it run well for?

Ben
On my 3rd Citroen. Saxo, Xsara, C5.
Jaguar S-type misfiring - Ron S
Hi,

My typical urban journey is about 2 to 5 miles. Long drives may be from 50 to 150 miles between engine turn-offs.

When misfiring has stopped on a long run, it does not return, even during the short journeys that may follow. But it does happen again on the next long journey.
Jaguar S-type misfiring - Malcolm_L
Italian tune-up required - but fill the tank with Shell Optimax before you do.

Plugs probably aren't getting hot enough to burn off carp.

Jaguar S-type misfiring - Ben79
Try some of the fuel additives recommended by others on this group.

It seems the best way to save your car is to drive it more. Find relatives in far away places to visit and once a week when the engine is hot, get close to the red line.

Ben
On my 3rd Citroen. Saxo, Xsara, C5.
 

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