OK guys, two seperate questions. One came about recently, the other has been going on for some time.

Recently I noticed that upon acceleration up hills my Van missing or not loses suction to the HVAC system. It switches from the dash vent (Bi-Level, norm/max A/C) to the off position (forcing air to the defrost and floor). Let up and it comes back up to where it was set. I cant seem to find any leaks or hear any.

Do these systems have a reserve canister or something?

OK next one has been going on for awhile. On hard acceleration the thing misses and cuts out hard and generally loses power. Particularly bad upon getting up to speed. Let up and it smooths out.

The EGR needle moves based on throttle position. I also replaced the idle motor recently (had two die) as well as the TPS and MAP sensor. No effect and no codes except 45, which it has always thrown (Think its transmission related).

This thing also burns rich especially at idle. Cold or warm it doesnt matter. But it pulled down 17mpg on a highway trip not exceeding 65 so I am wondering whats causing it. Around here the mileage is crap.

Its a 1995 B-series Van with the 3.9 and 904 trans. Any help appreciated. Hopefully I am overlooking something simple.