CAMPAIGN: LEAKING/PLUGGED EGR VACUUM PIPE ASSEMBLY
MODELS: 1983 "S" SERIES LIGHT DUTY TRUCKS EQUIPPED WITH RPO L02 2-OL L4 ENGINE
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 NOx and CO exhaust emissions.
To bring these vehicles into compliance with applicable emission requirements, GMC Truck Dealers will inspect, and if required replace, the EGR vacuum pipe assembly in accordance with the instructions outlined in this bulletin.
VEHICLES INVOLVED
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 D0500155 D0501385 Shreveport D8500445 D8500877 Moraine D2500748 D2501992
The specific vehicles involved in this campaign have been identified by Vehicle Identification Number Computer Listings. These listings are furnished to all involved dealers with the campaign 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 is in your dealership for service in the future, you should take the steps necessary to be sure the campaign correction has been made before reselling the vehicle.
On vehicles involved in this campaign that have been recently sold to a retail owner, where no owner's name and address were available to GMC Truck at the time of campaign initiation, the dealer will determine the owner's name and address from the dealership sales records. Please provide this information directly on the second copy of the listing next to the applicable VIN, so that our records may be updated and the appropriate notification mailed to the owner. This second copy should then be submitted to the address listed below in the previously supplied yellow campaign envelope.
GMC Truck General Motors Corporation 101 Union Street Plymouth, Michigan 48170
OWNER NOTIFICATION
Owners will be notified of this campaign on their vehicles by GMC Truck (see copy of Owner Letter included with this bulletin). A listing of owner names and addresses has been fumished to the involved dealers to enable dealers to follow up with owners involved in this campaign. This listing 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 this campaign.
SERVICE PROCEDURE
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 still cold (coolant temperature less than 115 F).
C. Replace vacuum supply line to distributor.
Step 2. Remove 4 port connector from air cleaner.
Quantity Part Number Per Vehicle Description ----------- ----------- ----------- 14058742 1 EGR Vacuum Pipe Assembly
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.
Step 3. Plug port 1 and 4, hook vacuum gage to port 3.
A. At idle, vacuum should read zero (0).
B. At off idle, vacuum should read 3-5" Hg. (A weaker signal than seen at port 1 when the throttle is stabbed).
Step 4. Plug ports 1 and 3, hook vacuum gage to port 4.
A. At idle, vacuum should read zero (0).
B. At an off idle throttle position, vacuum should read less than seen at port 3.
C. Crimp 1 1/4" long hose at EGR valve, vacuum should equal to reading at port 3.
If the engine is not fully warmed up (water temperature 160 F or higher), there will be no signal at port 4.
Vacuum readings that are not within the specification indicated in the inspection procedure of this bulletin indicate plugged or leaking EGR vacuum tubes which must be replaced. Access to the EGR vacuum tube assembly may best be accomplished by removing the intake manifold. In accordance with the instructions outlined in the 1983 Loose Leaf Service Manual (Ref. 2.0 liter L4, Pages 8 and 9).
PARTS INFORMATION
Parts are to be obtained from the Warehousing and Distribution Division of General Motors (WDDGM). To ensure that these parts will be obtained as soon as possible, they should be ordered from WDDGM on a C.I.O. order with no special instruction code, but order on an advise code (2).
WARRANTY INFORMATION
Dealers should submit an accurately filled out arranty Repair Order on each vehicle.
Labor *Time Operation Allow- Trouble Number Description ance Code
V1670 Inspect EGR 0.3 HR 96 vacuum pipe assembly (all models) for leaks and being plugged according to the inspection procedure outlined in this bulletin. Not plugged or leaking, no further action required.
V1671 Inspect, replace 2.3 HR 96 EGR vacuum pipe assembly (all models less A/C) leaking/plugged. Replace in accordance with the instructions outlined in this bulletin.
V1672 Inspect, replace 2.8 HR 96 EGR vacuum pipe assembly (all models with A/C) leaking/plugged. Replace in accordance with the instructions outlined in this bulletin.
*Dealers will receive 0.1 hours of Administration Time Detail associated with this campaign.
CAMPAIGN IDENTIFICATION LABEL
Each vehicle modified in accordance with the instructions outlined in this product campaign bulletin will require a "Campaign Identification Label". Each label provides a space to include the five (5) digit Dealer Code of the dealer performing the campaign service. This information may be inserted with a typewriter or ballpoint pen.
Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in for periodic servicing by the owner.
Apply "Campaign Identification Label" only on a clean dry surface.
ADMINISTRATIVE PROCEDURE
Procedures covering this campaign are outlined in Section V of your dealership's "GMC Truck Claims Processing Manual" issued October, 1981.
Dear GMC Truck Owner:
General Motors has determined that some 1983 GMC Truck "S" Series Light Duty Trucks equipped with 2.0 liter L-4 engines (RPO LQ2) may have leaking or plugged exhaust gas recirculating (EGR) vacuum pipe assemblies. These conditions may affect engine performance and increase oxides of nitrogen or carbon monoxide exhaust emissions.
To bring your vehicle into compliance with applicable emission requirements, GMC Truck Dealers will inspect, and if required, replace the EGR vacuum pipe assembly. This service will be performed at no charge to you. Please contact your GMC Truck Dealer on or after the date shown below to arrange an appointment to have this condition corrected.
Instructions for making this correction have been sent to your dealer. It is estimated that parts will be available at your dealer on or about June 20, 1983. The labor time for inspecting the EGR vacuum pipe is approximately 20 minutes; replacement will take an additional 2-1/2 hours.
The enclosed owner reply card identifies your vehicle. Presentation of this card to your dealer will assist them in making the necessary correction to your vehicle in the shortest possible time. If you have sold or traded your vehicle, please let us know by completing the postage paid owner reply card and returning it to us.
We are sorry to cause you this inconvenience; however, we have take this action in the interest of your continued satisfaction with our products.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
