GM Astro/Safari 1985-1996 Repair Guide

Backfire (Intake Manifold)


When the engine backfires through the intake manifold, replace or repair the following items or systems, as necessary:

Incorrect ignition timing.
Incorrect operation of the choke (carburetor equipped).
Choke setting (initial clearance) too large (carburetor equipped).
Defective Exhaust Gas Recirculation (EGR) valve.
A very lean air/fuel mixture (carburetor equipped).