GM Astro/Safari 1985-1996 Repair Guide

Engine Speed Oscillates at Idle


When the engine idle speed will not remain constant, replace or repair the following items or systems, as necessary:

A faulty fuel pump.
A leaky Exhaust Gas Recirculation (EGR) valve.
A blown head gasket.
A worn camshaft.
Worn timing gears, chain or sprockets.
Leaking intake manifold-to-engine gasket.
A blocked Positive Crankcase Ventilation (PCV) valve.
Overheating of the cooling system.