Jaguar stalls on extreme curve

jaguar
xj8

#1

The 1998 Jaguar “engine stalls” and I have no power when traveling over 55 on a sharp curve going from one freeway to another. It happens in exactly the same spot each time. If I am going under 50 it does not happen. Now it is also happening on the same area of a different freeway, again over 55 and the road has a slight downward angle and is going uphill. The car just shuts down - no warning lights until I pull over and then it says engine stalled. It starts right up and drives fine.


#2

Offhand, sounds like a fuel pump getting weak. I’m not a Jag expert but most pumps are set up to draw from a gasoline pool that is inside a baffle. This baffle prevents fuel starvation due to sloshing when cornering, braking, hills, etc.

The fuel level in the baffle area is also kept up by return fuel coming back from the engine compartment so a weak pump can not only drop the fuel pressure a bit it can also limit the amount being put back into the pool for the pump to draw from.

Any history of fuel filter changes? Filters should be changed about every 15k miles and even more often if they’re suspect.
It’s entirely possible for a car to run fine with a clogged filter but the downside is that fuel pump life can be shortened due to a clogged filter because it makes the pump work harder.

My daughter was out visiting this afternoon in her '05 Mustang and I did some routine maintenance on it while she was here.
The car runs great, has had no problems at all, but when dumped the fuel out of the filter looked like swamp water. It was also near impossible to even blow through it and this kind of reinforces my point that a car can run fine even with a clogged filter.
(And I’ve run into this twice in the last few weeks with other cars.)


#3

This is a known Jaguar problem for that model year and is covered under service action S514. In brief the problem is in the throttle body assemblies, on every fifth deceleration the butterfly in the throttle body closes completely, thus going through a cleaning process. The motor in the throttle body is not strong enough to overcome the engine vacuum and re-open, thus causing the engine to stall.

Please see the following Jaguar notification: http://members.cox.net/blackbeard2004/throttle%20body2.pdf