GMC T Series 1994 Repair Manual page 572

N O T IC E : U p p e r a n d l o w e r O - r in g s m u s t b e
i n s t a l le d b e f o r e in je c t o r s o r im p r o p e r s e a tin g
o f la r g e O -r in g c o u ld c a u s e f u e l to le a k .
• Injector, aligning raised lug on each injector base
with notch in fuel meter body cavity.
• Push down on injector until it is fully seated in fuel
meter body (figure 4).
• Electrical terminals of injector should be parallel
with throttle shaft.
FUEL METER COVER
-► 4- Install or Connect (Figure 2)
1. New fuel meter outlet passage gasket, and cover
gasket.
2. Fuel meter cover assembly.
N O T IC E : R e f e r to " N o t i c e " o n p a g e 6 C 1 -1 .
3. Attaching screw assemblies, precoated with Loctite
262 (P/N 10522624) or equivalent to the threads.
(Short screws are next to injectors.)
Tighten
• Screw assemblies to 3 N-m (28 lbs. in.).
THRO TTLE PO SITIO N SENSOR
(TP SENSOR)
Install or Connect (Figure 2)
-►4-
1. TP sensor seal over throttle shaft as shown in fig­
ure 2.
2. With throttle valve in normally-closed position,
install TP sensor on throttle shaft and rotate coun­
terclockwise to align mounting hole.
N O T IC E : R e f e r to "N o t i c e " o n p a g e 6 C 1 -1 .
3. TP sensor attaching screw assemblies, precoated
with appropriate thread-locking compound.
& Tighten
• Screw assemblies to 2 N-m (18 lbs. in.).
IDLE AIR CONTROL VALVE
N O T IC E : S in c e th e IA C
d u r in g s e r v ic e , it s o p e r a t io n s h o u ld b e t e s t e d
e l e c t r i c a l l y w it h t h e I A C / I S C
( J 3 7 0 2 7 o r B T -8 2 5 6 K ). H o w e v e r , i f th e v a lv e
p in t l e i s e x t e n d e d e le c t r ic a lly , i t m u s t a ls o b e
r e t r a c t e d e le c tr ic a lly . B e f o r e in s t a llin g a n IA C
v a lv e , m e a s u r e th e d is t a n c e b e t w e e n th e tip
o f t h e v a lv e p in t l e a n d th e m o u n t in g s u r f a c e
( "A " in f ig u r e s 5 a n d 6 ). i f t h e d im e n s io n is
g r e a t e r th a n 2 8 m m (1 .1 0 in c h e s ) , i t m u s t b e
r e d u c e d to p r e v e n t d a m a g e to t h e v a lv e . T h is
m a y b e d o n e e l e c t r ic a lly u s in g a n
m o t o r t e s t e r ( J 3 7 0 2 7 o r B T - 8 2 5 6 K ) o r m a n u ­
a l l y b y e x e r t in g f ir m p r e s s u r e w ith a s lig h t
p i d e - t o - s i d e m o v e m e n t o n
r e t r a c t i t (fig u r e 5 o r 6).
v a lv e w a s r e m o v e d
M o t o r T e s t e r
IA C /IS C
v a l v e p i n t l e to
Important
No physical adjustment of the IAC valve assembly is
required after installation. The IAC valve pintle is reset
by turning the ignition " ON" for ten seconds and then
" OFF." The ECM/PCM then resets the pintle to the cor­
rect position. Proper idle regulation should result.
+ 4 - Install or Connect (Figure 2)
N O T IC E : R e f e r to "N o t i c e " o n p a g e 6 C 1 -1 .
• IAC valve into throttle body as follows:
A. Thread-mounted valve
• Install with new gasket.
B. Flange-mounted valve
• Install with new lubricated O-ring, using
attaching screw assemblies.
Important
• New IAC valves have been reset at the factory and
should be installed in the throttle body in an "as is"
condition, without any adjustment.
A. DISTANCE OF PINTLE EXTENSION
B. DIAMETER AND SHAPE OF PINTLE
21. VALVE ASSY, IDLE AIR CONTROL
(IAC),(THREAD MOUNTED)
22. GASKET, IAC VALVE
Figure 5—Adjusting Valve Pintle (Thread Type)
A. DISTANCE OF PINTLE EXTENSION
B. DIAMETER OF PINTLE
24. SCREW, IAC ATTACHING
25. VALVE ASSY, IDLE AIR CONTROL
FLANGE MOUNTED
26. O - RING, IAC VALVE
3706r4864
3706r4865