Was it a fuel vapor lock of some kind?
 

OK, first thing I did was to do a search, however, I must not know what I'm looking for.

Wife called to tell me car was acting up,( knocking, sputtering, pinging,etc),about five miles into a new tank of Chevron 91 octane. She was afraid to drive it home as she thought it would stall. She didn't notice any warning messages.

I got to the car about 30 minutes later and first thing I checked was the fuel cap, which was on tight.(I remember a Jag tech saying a loose gas cap could present problems). I unscrewed it and I think I felt a small whoosh of air and did get a distinct smell of fuel coming out of the filler tube. (I don't think I've ever smelled that in any car.)

Anyhow, I started the car and it ran fine, and still is.

So my question is, what the hell happened and do I need to do anything further?

Thanks

If your wife drives like Arie Luijendijk and the temperatures are in the hundreds and the fuel lines are taped to the engine this might be the case: vapour lock.


By the way: if she does drive like him, the fuel won't have time to vaporize.


Old thing, really, with carburettor cars mostly.


My guts tells me the tank drew a vacuum. Just been filled up (easily vacuumated if I spell that correctly), the whoosh can be air coming in or going out, after 30 minutes it was ok.

She's a grandmother and drives like one :)
It was hotter than normal yesterday, close to 80 degrees and the "whoosh" could have been air being sucked in.
Anyhow, thanks for the reply.

The 91 octane may have been the issue. These cars are factory spec to be running on the TOP grade gas.

loose gas cap typically on any newer car will just throw a check light for mass air leak or the like.

Jaguar specifies 91 octane.

Google search for my 03 is Premium Unleaded which is 93 octane in my neck of the woods.

Yes, that's what is here also, but the spec is 91 min. There are a few members using 87 or 89 without problems. The knock sensors provide input to the ECU, which will retard the timing if necessary.

Simple answer: Your fuel evap/vapor recovery system was not working correctly.

You can't get fuel out of the tank to the engine easily if the system doesn't let air in, that is where the negative pressure came from when you opened the gas cap.

Have it checked out, it will probably happen again.
Vector

Thanks to all. 91 is the highest we can get in San Diego.

I think Vector is right. More of a Vacuum lock than a vapor. Vapor lock is old school where the heat build up is so bad in the carburetor, the fuel starts to boil. Your dilemma could be something as simple as overfilling the tank. Most manufactures will tell you to stop filling once the pump clicks off the first time. If not, you can disturb the evaporation system. If so, just don't do it again. My other thought is bad fuel. Excessive water in fuel. If that is the case, you Jag will start to run poor as the tank empties. I kinda lean toward my first thought. good luck. Rich

Me again. Lets not get started on the octane thing again guys, ok ? Rich