as posted by Stu @ M Developments


Briefly:
The KE Jetronic system has ELECTRONIC enrichment via the black box.

This enrichment box is responsible for:

Choke:
Additional fuel when cold to make her start.

Part load accel:
Additional fuel when accelerating.

Full Load Accel:
This is the important one. This ecu is responsible for increasing the differential pressure in the metering head and thus givig you the extra fuel for the boost.

Fuse:
The ERST has a different wiring harness to the normal escorts and the heated seats fuse is in fact the engine management fuse on an RST loom. Sadly, Ford didnt ever bother making a new lid for the box to illustrate this fact