SC cold idle problem
 

Car simply dies when idling going downhill when cold, and will not restart, anybody else run across this? CIS injection, new (rebuilt) WUR, runs like a charm when warm,

My driveway is steep and I do not like to have to let it warm up for 5 minutes and stink up the garage,

aux air regulator work ? should have high idle after initial start 1400 rpm for a few minutes what year is car? 82,83 models have enrichment computer under passenger seat along with oxs control unit. check fuse for oxs system same as dome light fuse. do dome lights work? a few things to try.

CHT or fuel pressure.

Check your cold control pressure, WUR may have moved out of spec.

Motor is in a '74, and is an un-numbered motor, (which I understand indicates a warranty replacement motor?)

It is going back in the shop soon, but the dying going downhill is the confusing part,

What cold start set up do you have, the original hand enricher or the SC set up with cold start valve? If you have a hybrid, this could be the source of your problem.
Also in NI, 83801.

What could a change of gravity direction impact?

Air flow sensor that has a little sideways play?
Fuel location in tank?
Wire that gets grounded from moving?

Seems those all would happen when warm as well.

Dumb idea - could it be a motion sensor? I know that my old MGB had this thing under the dash that was supposed to cut off the fuel supply if the car tipped over.

A long shot at best, but stranger things have happened.