I am picking up a '93 with the 3vz-e this week.one of the mechanical issues is when coming to a stop,press brake pedal,push clutch pedal in and the motor wants to stall but it doesnt.
Seller says its related to a couple of vacuum lines which are plugged off from what he can gather.
Could it possibly be the power steering air control valve?I am going to attach a pic which isnt the clearest but there are 2 vacuum lines which have screws to plug them off on the left side in amongst the winch wiring.

 

Since it's brake related, sounds more like a leaking booster. But you're on the right track trying to get the vacuum hoses sorted. The 3vze runs much better when the vacuum hoses are connected properly and not leaking. Check for a sticker under the hood for proper routing.

 

Its deffinatly vacuum related.just went to see the truck last night.put a deposit and pick it up midweek.seller has done 90% of the mechanical grunt work but there is a few small issues.cant wait to get it.