GM Caprice 1990-1993 Repair Guide

Fuel Vapor Canister


See Figure 1

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Fig. Fig. 1: Vapor canister location - 1991-93 Caprice

To limit gasoline vapor discharge into the air this system is designed to trap fuel vapors, which normally escape from the fuel system. Vapor arrest is accomplished through the use of the charcoal canister. This canister absorbs fuel vapors and stores them until they can be removed to be burned in the engine. Removal of the vapors from the canister is accomplished by a solenoid operated bowl vent or vacuum operated purge valve mounted on the canister. In addition to the fuel system modifications and the canister, the fuel tank requires a non-vented gas cap. The domed fuel tank positions a vent high enough above the fuel to keep the vent pipe in the vapor at all times. The single vent pipe is routed directly to the canister. From the canister, the vapors are routed to the PCV system, where they will be burned during normal combustion.


  1. Tag and disconnect all hoses connected to the charcoal canister.
  3. Loosen the retaining clamps and then lift out the canister.
  5. Grasp the filter in the bottom of the canister with your fingers and pull it out. Replace it with a new one.
  7. Install canister and tighten retaining clamps.
  9. Install all hoses to canister.

Some vehicles do not have replaceable filters.