Had this happen to me today...I have a 2004 XJ8...

Was driving on the freeway at about 65MPH when the engine suddenly lost power. The car slowed down and I had to pull over to the right shoulder before it stopped in the middle of a lane.

The starter would crank the engine, but it would not turn over. I was left stranded on the side of the freeway (never a good thing).

Unable to start it, I had it towed home.

Once at home, I tried to start it. Again, it would crank but the engine would not turn over.

Then I remembered about the Inertia Switch. I reset it and lo and behold the engine finally came to life. I have a message in the message center that says "Restricted Performance", but at least the car turned on and I could drive it some.

So the question is: "Do these inertia switches go bad like this while driving? Or is this a symptom of something worse?" Are these inertia switches on the 350's prone to failure?

Not sure why I have "Restricted Performance" showing the message center after resetting the inertia switch, but of course, I'm going to have it checked out.

I recently had the car re-programmed to have the daytime running lights turned off (the lights used to be on during the day when lights were in "auto" mode) and since then, I've noticed that the trunk/boot lid will get "confused" a lot and not latch properly unless I open the lid, flip the latch closed and then push the trunk button to make it think it just released (then I can close the lid, give it push and it will latch tight).

Thanks to anyone with any insight on it. I'll post what my tech finds later this week.

 

That is strange. I had that happen when a passenger kicked it accidentally in my '95 XJS. On that car it is located right by the passenger's feet. Not sure where yours is??

 

Update: My tech says it's a fuel pump problem and that I need it replaced. I trust him so I'm going ahead with the repair (but my first thought to be honest was that it was a TB problem).

 

fuel pumps can fail 'just like that'

Your tech can check the fuel pressure easily since there is a schrader valve on the fuel rail.

 

On mine it's on the left side (driver's side) next to my left foot in the footwell.