Emissions - Inoperative EGR Valve
SUBJECT INOPERATIVE EGR VALVES NUMBER: 86-T-32DATE: April 22, 1986
MODELS/YEARS 1986 CUTLASS CIERA & CALAIS MODELS
WITH 2.5L L4 ENGINE LR8 (VIN CODE R) SECTION: 6E
AND L68 (VIN CODE U)
Some 1986 Cutlass Ciera and Calais models with a 2.5L L4 engine may exhibit excessive spark knock at part throttle, due to an inoperative EGR valve.
If an EGR valve has been diagnosed as inoperative because it does not respond to a normal vacuum signal, remove the vacuum hose and check the orifice in the vacuum fitting for a plugged condition. The orifice may have excessive, hardened, hose assembly lubricant blocking it. If this condition exists, clear the orifice with a small wire or pin, return the vacuum hose to the fitting, and test the EGR valve for function.
If the EGR is still inoperative, replace it.