Missing at idle

We have a 93 Silhouette. It is missing at idle but seems to go away when you pull out. I cant find a vacuum leak but was wondering what the vacuum pressure should be. The TBI was also recently rebuilt along with a new fuel filter, and fuel pump, wires, plugs, cap and rotor.

I want to change the pickup, EGR, and MAP sensor that way I know they are new.

What I would like to know is if there is any particular things that seem to go wrong with the car. Something that goes bad more then normal or is common on the vans.

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