1987 Chevy Astro Van,4.3L A/T,P/S,CA Emision ,AIR Pump,EGR,PCV. well here it goes. Poor Idle in gear. Has poor Exceilaration,lacks Power. Has low Vacuum reading (15 in.) in gear (17in)out of [...] pressure is 15 psi at idle, WOT 12.5 psi. .I have high map read... Login to read more.