Volvo 819 E - Page 29

Group 28 Ignition systems
Design and function Regina fuel injec t ion
REGINA
3
1
--
REX-I
REX-I
'<17520
Regina fuel injection system
General
The injec tion system con tr ol unit (1) supp lies the ignition system control unit (2) with information on engine load-
acting, in other words, as a 'sensor' for the latter.
The gas pressure in the cylinders dur i ng the compression stroke will rise as a greater charge of fuel/air m i xture is
supplied to the engine , and the ignition system will retard the tim ing according as engi ne load increases.
Si gn als
The electronic pressure sensor (3) and air temperature sensor (4) supply voltage signals to the Regina co ntrol unit
Ill. Taken together , these si gnals provide a measure of eng ine load and are processed by the Regina control unit to
com pute the quantity of fuel to be injected. Once the load signals have been converted into digital form (i.e. into
square-wave pulses), they are transmitted to the Rex -I control unit (2).
The
digital signal consists of current pulses (5) of a duration (6) proportional to the engine load .
• Should the load signal from the Regina control unit be lost for any reason, the ignition system control unit w ill compute the tim-
ing on the basis of max. loa d conditions, provided that the id ling swi tch is not closed.
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