Hi,
My '96 XJR has an aversion to starting when facing downhill!

This usually happens in warmer weather and is worst when the car has been left hot for around 10 mins. If I park it facing uphill in the same conditions away she goes. Eventually, after some cranking, it will start,but reluctantly.

We are thinking vapour lock, but why only when the front of the car is lower than the rear?

Thoughts appreciated,
Richard.

 

Just a long shot and probably too simple, but is it possible that some sludge or other blockage is causing the issue? Maybe blocking the fuel uptake when the car is only in a particular position?

Maybe try to raise the car on one side or the other while it is parked facing downhill and see if it starts. This might suggest that something inside the tank is moving about. A bit crazy but a cost free test!

 

I would look in the intake duct. There is a tendency for oil to collect in that area. A lot of oil. Could even get to your air cleaner. Easy to have a look.