Just as the title says. I assume that this is a vacuum issue. where should i look for this problem? I looked at the vacuum tree on the firewall and see no leaks. The weird thing is, if I push down the accel in park, it doesn't happen, only when it's actually in gear and under load. Is that just a symptom of the way that the vacuum system works? Also, anyone have a full vacuum diagram for an 89 2.3?