Recently I posted thanks to the person who advised me to clean the idle
control valve.  After I'd removed the throttle body and given a good
blast with carb cleaner the car started and I thought all was OK.  Not
so.  I later went for a long drive and the car ran well, but when I
stopped a couple of times it was reluctant to start again.  We got home
OK, but the next time I tried to start it the same problem was there.  I
have just taken the throttle body off again, and this time taken the ISC
valve assembly off so I could clean out the valve more thoroughly (yes,
I marked the position for reassembly).  Back together, the engined fired
briefly then stopped and failed to fire again.  Battery is good, the
engine turns over well.

I think the ISC valve has been eliminated from consideration, so what
else should I look at? (I've already replaced fuel the filter).  As far
as I can see almost everything else is electrical/computer, and I don't
think I have the ability to test these parts.  The engine ran perfectly
on the trip, and the starting problem was evident, though not so
conclusively, when the engine was hot.

Any suggestions from the mechanics out there?

Thanks...