K 1500 Truck 4WD V8-454 7.4L (1988)
View E
E. Add one additional 3/16" hole to plastic bracket and two 1/8" holes in air cleaner at proper location, using revised bracket as hole template
(Views C and D).
F. Mount bracket so map sensor vacuum connection faces down toward engine, using two 8-3x1/2" sheet metal screws, P/N 447164.
G. Install vacuum hose harness, P/N 10129600 (see Views D and E).
Important
On trucks not equipped with an accessory vacuum fitting in the manifold, install fitting, P/N 14088336 and use caps, P/N 343350 to plug any
unused port.
H. Reinstall electrical.
4. On 1987-89, Check the control idle speed.
A. On fully warm engine, Spec. is 750 RPM in Drive for automatic transmission and 800 RPM in Neutral for manual transmission.
B. IAC counts on both transmission should be between 5-30 counts.
^
If the control speed is not within the above specifications, a minimum idle speed adjustment must be made using the procedure shown on page 4-20
of the 1991 Light Duty Fuel and Emissions Manual.
5. Install latest PROM as shown in PARTS INFORMATION.
6. The Dealer should tell the customer that the Cold Start Procedure has been revised from that shown in the Owner's Manual. After initial
fire and run, the throttle should be cracked to about 1/4 to clean raw gas from the intake manifold.
PARTS INFORMATION:
TRANSMISSION
AXLE
NEW PROM KIT
NEW BROADCAST
NEW SCAN TOOL
CODE
I.D.
Auto (M-40)
ALL
16169157
AZFT
9171
Man (M-20)
3.73 (GT4)
16169158
AZFU
9181
3.42 (GU6)
"
"
"
Man (M-20)
4.10 (GT5)
16169159
AZFW
9191
4.56 (HG4)
"
"
"
Parts are currently available from GMSPO.
WARRANTY INFORMATION:
LABOR
OPERATION
LABOR TIME
NUMBER:
Relocating Map
Sensor
T7500
0.3 Hours
Replace PROM
T0500
0.6 Hours C/K,
R/V
0.7 Hours G/P
Technical Service Bulletin # 89263A6E
Date: 911101
PROM - Surge, Detonation or Code 32, EGR
Number: 89-263A-6E
Section: 6E
Date: NOV. 1991
Corporate Bulletin No.: 136516
