S10/T10 P/U 2WD L4-121 2.0L VIN Y 2-bbl (1983)
Technical Service Bulletin # 83C04
Date: 830601
Engine - Leaking/Plugged Vacuum Pipe Assembly
Number:
83C04
Section:
VI
Date:
June, 1983
Subject:
PRODUCT EMISSION CAMPAIGN 83C04 LEAKING/PLUGGED EGR VACUUM PIPE ASSEMBLY - 1983 "S" SERIES LIGHT
LQ2 2.0L L4 ENGINE
TO:
ALL INVOLVED CHEVROLET DEALERS
General Motors has determined that certain 1983 "S" Series Light Duty Trucks equipped with RPO LQ2 2.0L L4 engine may have leaking or plugged
EGR vacuum pipe assemblies.
These conditions may affect engine performance and increase the NO(x) and CO exhaust emissions.
To bring these vehicles into compliance with applicable emission requirements, Chevrolet Dealers will inspect, and if required replace, the EGR vacuum
pipe assembly in accordance with the instructions outlined in this bulletin.
Vehicles and Owner Information
Involved are certain 1983 "S" Series Light Duty Trucks equipped with RPO LQ2 2.0L L4 engine within the following vehicle breakpoints:
Plant
From
Through
Pontiac
D0100468
D0104610
Shreveport
D8100638
D8105074
Moraine
D2102710
D2110724
Involved vehicles have been identified by Vehicle Identification Number Computer Listings. Computer listings contain the complete Vehicle
Identification Number, owner name and address data, and are furnished to the involved dealers with the campaign bulletin. Owner name and address data
furnished will enable dealers to follow-up with owners involved in this campaign.
These listings may contain owner names and addresses obtained from State Motor Vehicle Registration Records. The use of such motor vehicle
registration data for any other purpose is a violation of law in several states. Accordingly, you are urged to limit the use of this listing to the follow-up
necessary to complete this campaign. Any dealer not receiving a computer listing with the campaign bulletin was not shipped any involved vehicles.
OWNER NOTIFICATION
Owners will be notified of this campaign on their vehicles by Chevrolet Motor Division (see copy of Owner Letter included with this bulletin).
DEALER CAMPAIGN RESPONSIBILITY
Dealers are to service all vehicles subject to this campaign, regardless of mileage, age of vehicle, or ownership, from this time forward.
Whenever a vehicle subject to this campaign is taken into your new or used vehicle inventory or it is in your dealership for service in the future, you
should take the steps necessary to be sure the campaign correction has been made.
Service Procedure, Parts and Claim Information
EGR Pipe Inspection Procedure
Step 1. Disconnect vacuum line for distributor vacuum advance can and connect a vacuum gage to removed vacuum supply line.
A.
Start engine and warm up until base idle is achieved. (Throttle must be kicked to attain base idle, not on fast idle cam). Idle vacuum should read
5-6" Hg.
B.
Move throttle to off idle setting, vacuum should read greater than idle setting. Note: A rapid drop of vacuum should result when throttle is moved
quickly, a slow response if the engine is still cold (coolant temperature less than 115~F).
C.
Replace vacuum supply line to distributor.
Step 2. Remove 4 port connector from air cleaner.
A.
With a vacuum gage attached to 1, vacuum at idle should read 9-14" Hg. A rapid drop of vacuum should result when throttle is stabbed.