GMC 1989 Light Duty Truck, Repair Manual

Page: 637 / 998

MODEL 700 THROTTLE BODY 6C4-5
IDLE AIR CONTROL (IAC) VALVE
N O TIC E: The IA C valve is an e le c tric a l c o m p o ­
n e n t a n d m u s t n o t b e so a k e d in an y liq u id c le a n e r
o r solvent. O th e rw is e d a m a g e c o u ld result.
Important
On TBI Model 700, the IAC valve is flange-mounted,
with dual taper, 10mm diam eter pintle. If replacem ent
is necessary, only an IAC valve identified with the
correct part num ber (having the appropriate pintle
shape and diameter) should be used.
Remove or Disconnect (Figure 9)
1. Screw assemblies and IAC valve.
2. IAC valve o-ring and discard.
3. T hrottle Position S ensor
4. TPS A ttaching S crew & W asher A ssem bly
F-6755
TUBE MODULE ASSEMBLY
Remove or Disconnect (Figure 10)
1. Tube module assem bly attaching screws.
2. Tube module assembly.
3. Tube module assem bly gasket and discard.
Figure 8— Throttle Position Sensor (TPS) TBI 700
3
2
1. IA C V Attaching S crew A ssem bly
2. External IA C V O -R ing
3. G rim e Shield
F-6739
Figure 9— Flange Mounted IAC Valve — TBI 700
CLEANING
jtrp
Clean
Metal throttle body parts in cold im m ersion type
cleaner, Carbon X (X-55) or equivalent.
N O T IC E : Do n o t im m e rs e IA C Valve, T h ro ttle
Position Sensor, Fuel In je c to r o r Pressure R e g u ­
la to r in c le a n e r as th e y m ay b e c o m e n o n -fu n c -
tional.
Old gasket material from surface of throttle body
assem bly to insure proper seal of new gaskets.
IAC valve seating surfaces on throttle body to assure
proper seal of new O-ring and contact of IAC valve
flange.
Blow out all passages in the castings with co m ­
pressed air. Do not pass drill bits or wire through
passages.