Hot Weather Issue

[gregorcarp]

Whenever the air temp gets over about 100 degrees our '95 Jayco with the Ford 360 often stalls even though the engine temp gauge is reading normal. Could this be some kind of fuel problem (i.e. vapor lock), or could it be something else? I had the "brain box" replaced a couple of weeks ago because the Ford dealer thought that was the problem based on the codes he read, but it still stalls. If we wait a half hour or so it will run normally again for a short (20-30 miles) distance before stalling again. Very inconvenient if living year round in Arizona!

[Witt74]

Sounds like vapor lock, although with the fuel injected engines, I would have thought vapor lock was a thing of the past.

[gregorcarp]

Just found this information: "The problem is caused by the thick film ignition ("TFI") modules, a key ignition-system component that Ford installed in more than 22 million vehicles it manufactured and sold in the 1983 through 1995 mode years. The TFI module regulates the electrical current that fires the air-fuel mixture in each of the engine’s cylinders. To reduce costs, Ford installed the TFI on the distributor, one of the hottest locations under the hood. But because the TFI module is sensitive to heat, its mounting location creates an inordinate propensity for the TFI module to fail due to thermal stress. Making the problem even more insidious is its phantom nature. A TFI module can fail on an intermittent basis when hot, then function again when the engine cools, without leaving a trace of physical evidence that the TFI module had failed."
Sounds awfully familiar. Wonder if they came up with a retrofit to solve the issue.