Engine - Hesitation/Sag on Hard Acceleration

Number: 84-172

Section: 6C (VIm)

Date: July, 1984

Subject: REDUCTION IN PERFORMANCE UNDER HARD ACCELERATION ON 5.0L V8 4BBL ENGINES (LG4)


Model and Year: 1982-84 CAMAROS

TO: ALL CHEVROLET DEALERS

Some Camaros with the LG4 engine may experience a reduction in performance in the form of hesitation or sag under hard acceleration. This condition usually occurs at high ambient temperatures when the engine is hot and may be due to fuel vapor lock. Vapor lock is temporary fuel starvation that is most likely to happen upon acceleration after a short soak or extended idle period.

To alleviate this condition, it will be necessary to replace the fuel pump with service kit, P/N 6472366. This new pump utilizes a smaller return line orifice.

Pumps that may require replacement can be identified by the last five (5) digits of the part number stamped on the bottom side of the pump mounting flange. They are as follows:


Vehicle Year I.D. Number

Early 1982 42076

Interim 1982, All 1983-84 41265


Follow replacement procedures as outlined in the appropriate Camaro shop manual.


Use applicable labor operation.