An update on this problem, and its solution...

Turns out it was the primary fuel mixture cut-off solenoid valve on the
carb. Since it is only supplied with one positive voltage wire, it gets
ground from its attachment to the carb. I figured it out when I removed
it and covered the hole in the carb with tape. The car did not stall
when the valve was not installed. I scratched up the mounting surfaces
with sandpaper and all is well. The solenoid valve itself is fine.

I did replace a bunch of vacuum lines and cleaned the distributor. In
the process, I learned a lot more about this car.

dan

dan wrote:
> For the last few weeks I've been trying to fix this stalling problem.
> I've owned this 88 LX carbed 5-speed with 145K miles since it was new,
> and I want to keep it forever.
>
> The car starts and runs as normal, except lately it intermittently
> stalls out at idle. Not the best situation in stop and go traffic! It
> always restarts, and will run if the idle is held over 1000 RPM. If I
> let it idle, it will eventually stall out.
>
> I looked for the obvious vacuum leak problems and replaced one of the
> vacuum valves that was bad. (Frequency Solenoid Valve B)
> I have lately replaced the PCV valve, and just checked it again.
> I just cleaned and checked the EGR valve and reinstalled it with a new
> gasket
> I have recently replaced both fuel filters and today replaced the fuel
> pump. The gas tank was clean inside.
> I just adjusted the fuel level in the float bowl, after pulling the carb
> top and checking that the bowl looked clean.
>
> What else could the problem be???
>
> dan