850 T-5R L5-2.3L Turbo VIN 58 B5234T5 (1995)
Thermostatic Air Cleaner Actuator: Technical Service Bulletins
Preheated Air - New Control Method
Section
2
Group
25
No.
818
Date
August 1997
Preheating air
850
REFERENCE: TP 2101201, SECTION 2 (20-22, 25-26) B5204, B5234, B5252, B5254 ENGINES; 850 1992-
This Service Bulletin supplements section "Group 25 Intake and exhaust systems, paragraph CA. Preheating Intake air. check" in Service Manual TP
2101201.
Write In "Also see Service Bulletin 2-25-818" Immediately beneath the heading "CA. Preheating Intake air, check" in Service Manual TP 2101201.
New control method for preheating air
The design and function of the preheating air system, fault-tracing, and procedure for replacing components, are all described in this Service Bulletin.
The system controls the intake air temperature so that it remains between +27°C (81°F) and +37°C (99°F) in the 850.
Function
The intake manifold vacuum in the plastic tubes is distributed from the multi-nipple (1) via a bimetal sensor-controlled damper (2) to a vacuum tank (3)
which controls a damper, which opens and lets hot air into the cold intake air. When the throttle is wide open no vacuum is created and the air damper
remains closed.
When the outside temperature is cold and with wide open throttle (WOT), the center damper is held open by a wax thermostat (4), which is located
between the vacuum tank and the center damper.
Checking the system
Remove:
-
cold air hose.
Check:
-
that all vacuum tubes are properly connected