Idle slows and stops after revving

[fixkick]

you did the tuneup and skipped the fuel filter
at all tuneups, its best practice, on all Distributors engines made to , check spark timing.
did the new engine (i bet it was just used, and not new or rebuilt.
was the engine , refreshed 3 years ago with a new cam belt,.?
if engine or belt was ,new, no matter which was, the 120k, is 20k past the 100k life of the belt.
the belt lasts for 100km , and fails about 30 to 60k mile beyond the stated service point, (in the book on this engine)
so how many miles are on this belt. seems 120k + even double. if engine was old.
as you can see i do not know the service history at all here.