1975 - 1982 Corvette: Service Bulletin: Viton Accelerator Pumps - Current and Past Models Equipped with Dual and Quadrajets

Subject:   Viton Accelerator Pumps - Current and Past Models Equipped with Dual and Quadrajets
Model and Year:   1975 - 1983 Chevrolet Vehicles Equipped with Dual and Quadrajets
Source:  Chevrolet Dealer Service Information Bulletin
Bulletin No:   83-I-65
Section:   VIm
Date:    May, 1983

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.

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" flat 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 .

Viton service replacement pumps are identified as H.D. (Heavy Duty) in the parts book and are shown in Figure 2.

Applications are as follows:

Red lip (with garter spring)  -- Machined well only (MW)

Blue, thin lip -- Non-machined well only

Dual and quadrajet pump part numbers:

Red lip (with garter spring) -- 17072978

Blue, thin lip -- See parts list

Chevrolet Motor Division
General Motors Corporation