Idle Air Control Valve C2-7; Fuel System Pressure Test; Port Fuel Injection Componentsc; Fuel Pressure Relief Procedure - Pontiac Fiero 1988 Service Manual

DRIVEABILITY A N D EMISSIONS - FUEL INJECTION (PORT) 6E3-C2-7
If the block learn values are less than 118, see
Code 45 for Items which can cause the system to run
rich. If a driveability symptom exists refer to the
particular symptom in Section "B" for additional
items to check.
IDLE AIR CONTROL VALVE
A "Scan" tool will read idle air control (IAC)
position in steps (counts). "0" steps indicates the
electronic control module (ECM) is commanding the
IAC to be driven all the way in, to a fully seated
position, and this is usually caused by a vacuum leak.
The higher the number of counts, the more air is
being allowed to pass the IAC valve. If the IAC valve
is unable to control the idle speed within 100 rpm of
the ECM commanded speed, a Code 35 should set. A
Code Chart should be used to diagnose the IAC
system. Refer to "Rough, Unstable, or Incorrect Idle,
Stalling" in the Symptoms Section "B" for other
possibilities for the cause of idle problems.
FUEL SYSTEM PRESSURE TEST
A Fuel System Pressure Test is part of several of
the Diagnostic Charts and Symptom checks. To
perform this test, use the procedure on the page
opposite CHART A-7.
ON-VEHSCLE SERVICE
PORT FUEL INJECTION COMPONENTS
CAUTION:
To prevent p e r s o n a l injury or
damage to the vehicle as the result
of an accidental start, disconnect
and reconnect the negative battery
cable before and after service is
performed. (Where Delco-Loc
t m
radio is installed on Pontiac cars,
refer to NOTICE in beginning of
Section "9A" to reactivate radio).
CAUTION:
To minimize the risk of fire, and
personal injury, relieve the fuel
system pressure before servicing
the fuel rail, or any of its fuel
handling components. (See "Fuel
P r e s s u r e Relief P r o c e d u r e , "
below)*
CAUTION:
Also, catch any fuel that leaks out
when disconnecting the fuel lines,
by covering the fittings with a shop
cloth. P l a c e t h e c l o t h in a n
approved container when work is
complete.
25 N-m
( 1 8 F T . L B S . )
25 N-m
( 1 8 F T . L B S .
PH I N T A K E M A N I F O L D
[T]
G A S K E T
FTI
F U E L R A I L A S S E M B L Y
[T]
P L E N U M
5S 1468-6E
Figure
C2-12
- R e m o v i n g
Plenum and
Fuel Rail
FUEL PRESSURE RELIEF PROCEDURE
1.
2.
Connect fuel gage J 34730-1 or equivalent to fuel
pressure valve. Wrap a shop towel around fitting
while connecting gage to avoid spillage.
Install bleed hose into an approved container and
open valve to bleed system pressure.
PLENUM
R e m o v a l a n d I n s t a l l a t i o n ( F i g u r e C2-12)
Removing the fuel rail assembly from the engine
requires removing the top portion of the tuned intake
manifold, called the "plenum".
j+Hijj
R e m o v e o r D i s c o n n e c t
1. Vacuum lines, noting location of lines.
2. EGR pipe to EGR valve base bolts.
3. Throttle cable bracket bolts.
4. Throttle body bolts.
5. Plenum bolts.
6. Plenum and gaskets. Discard gaskets.