C 20 3/4 Ton Pickup 2WD V8-350 5.7L VIN L 4-bbl (1983)
Technical Service Bulletin # 83I65VIM
Date: 830501
Accelerator Pumps, VITON - Available
Number:
83-I-65
Section:
VIm
Date:
May, 1983
Subject:
VITON ACCELERATOR PUMPS - CURRENT
AND PAST MODELS EQUIPPED WITH DUAL AND QUADRAJETS - 1975-83
TO:
ALL CHEVROLET DEALERS
Viton accelerator pumps are now available from WDDGM for service when a customer is using a high aromatic fuel, gasohol or has dry-out
conditions stemming from long periods of non-operation.
Two (2) types of viton accelerator pumps are released and must be used in the correct float bowl assembly.
FIGURE 1. (DUALJET SHOWN) CARBURETOR
Float bowl assemblies that have the letters "MW" (machined well) embossed next to the throttle position sensor electrical connector use the
red lip (with garter spring) viton accelerator pump only. See Figure 1.
Some 1982-83 "MW" float bowl assemblies used during production were assembled with the red viton pump and some were not. If the float
bowl assembly does not contain the red viton pump, a blue dot will be on the rear of the throttle body near the bolt hole. See Figure 1.
If the letters "MW" are not on the float bowl assembly a blue, thin lip accelerator pump can be used per the part list included with this
bulletin. This float bowl assembly has the non-machined pump well and uses the blue, thin lip accelerator pump only.
