Lumina APV MAP sensor

I was wondering if there is a MAP sensor on a 93 3.8L V6 in a Lumina APV . The van has erratic idle and very poor acceleration . Gets a little better when it's warmed up . Any suggestions . I tried another ECM , same result . The sensors have been tested on a scanner . They all looked fine . The timing was always off and changing . Between -8 & +5 at idle speed . The Mass airflow sensor was give high readouts . 15 at idle instead of about 7 ?????? .So i was guessing on the map sensor , but can't find it ????? .
Thank you in advance