94 Crown Vic intermittent dying in turns

A friend of my mother-in-law has a Crown Vic LX, V8, that keeps dying on her intermittently. She says that it usually does it in turns but sometimes it is fine. What should the mechanic be looking for when she takes it in?

The prime suspect should be the idle air bypass valve (also sometimes called the IAC). Ford has a redesigned part out now that is much less likely to stick than the one that came with the car.

Does it make any difference if the fuel tank is full or near empty?

I will tell the lady about the IAC. Thanks for the information.

I do not believe so. It sounds like it is truly intermittent with regards to when she drives it, whether full empty, short distances vs long distances, running the a/c or not.