4A l0 EMISSION CUNTll0LS EXlllll ST SYSTEMS VI i position allowing air pump pressure to flow to the ex haust manifold sp it is gt Divartur Tas M 1 Start engine and let idle 2 Check diverter vents Little or no air should WUOD BLOCK flow from vents B 3 Accelerate engine to 2000 to 3000 rpm and 3 rapidly close throttle A strong flow of air should pass W from the diverter vents If air does not flow or if back W V T fire occurred make certain vacuum sensing line has gf W vacuum and is not leaking q L 4 1 at NOTE The diverter valve dwerts mr pump output J M when 20 inches of Hg or more is applied at vacuum x Q sensing line orpump outputexceeds 5psi A W V 4 Slowly accelerate engine Between 2500 and l en 3500 rpm air should begin to flow from diverter 6 vents s g V mm Divanor Ilaplaoamani The diverter valve is not serviceable and must be Fiq M 6 Exhlusllubtlnsillllilull replaced if defective The valve is suspended by the hoses between the air pump and air injection manifold s fig 4A 1 and 4A 2 Removal involves dis using a block of wood until approximately 7 8 inch of connecting the hoses and the vacuum sensing line In tube extends above the cover itallation entails reconnecting the hoses and vacuum ine DIVERTEII BVl ASSl VALVE v nom A diverter valve is used in all Air Guard applica DIA H QQQTSQAGM tions The valves for V 8 and six cylinder engines dif fer only in the number of outlets The V 8 diverter H VACUUM valve has two outlets and the six cylinder diverter SENSING valve has only onc The valve momentarily diverts air umm pump output from reaching the exhaust during rapid deceleration and acts as a pressure release when air i pump output is excessive An internal silencer is incor I lj porated in the diverter housing to muffle the airflow j l w ln a rapid deceleration condition high intake manifold vacuum is applied to the diaphragm in the diverter When the vacuum signal is 20 inches of mer OUTLET 3 cury or more the spring tension of the diaphragm is 10 Am I overcome This moves the metering valve down wizfg igl against its upper seat and away from its lower seat R forcing air pump output to vent to atmosphere fig 4 Ain 4A 7b Air pump output is diverted only momentarily U because of a bleed hole in the diaphragm This hole 9 allows vacuum to quickly equalize on both sides of the 0 4 a diaphragm and the diaphragm spring returns the J metering valve to its normal position g I Tg L NER AND lf the air pump develops excessive output pressure ERESSURE this pressure will overcome the diaphragm spring ten SESEQISEYLEY sion pushing the metering valve down and venting VALVE N pump output pressure to the atmosphere When pump evuss output pressure returns to normal the metering valve POSITION AWZ77 will move up and away from the upper seat and against the lower seat returning to its normal open Fly MJ D v r1 rV Iv0 V 8 Slmvml