No speed signal ?
The kick down relay is fed of that rpm feed from EZK to LH. The rev counter (tach)
is also fed from the same point.
Those pulses are required to wake up the LH, so it energizes the fuel pump relay
and also pulses the injectors.
If your tach flickers when cranking the engine, then that would usually indicate
all is well with the pin 13 EZK --->> pin 1 LH feed.
A helper should also be able to hear the fuel pump whine when you crank the
engine.
Then confirm that the injectors are pulsing when cranking, as Bill has
suggested.
====
This picture shows the signal path of the speed (rpm) signal for a 1988 928S4. Click on the picture to see a detailed view.
====
This is the signal path for a 1991 928S4 (and probably for all 1989-1995 models the same or very similar):
TDC Pickup generates the signal for the EZK. EZK sends a processed RPM signal via pin 13 to the LH ecu pin 1 which makes the LH know the rpm and timing for the injectors. From the same pin 1 of the LH, a wire goes to the kickdown relay 31b end also to M11 of the central electrics board. From M11 a wire goes to the diagnostic socket pin 14, and also to the instrument cluster plug 4 pin 7.
regards Theo
1992 928GTS midnight blue