94 Olds 88 just randomly quits running while driving. will restatrt after a few minutes

Have you serviced the transmission? It could be a clogged filter or contaminated fluid. Get serviced by a reputable vendor.

COULD BE SPEEDOMETER CABLE BROKEN OR WORN SPEEDOMETOR DRIVE GEAR OR BROKEN GEAR.

Here's a link to the serptentine diagram for our '94 Olds 88 Royale...

http://www.gates.com/common/part_locator/view_diagram.cfm?id=S6005

The max infaltion will be stamped on the tire itself, I would inflate to manufaturer spec., which will be on the drivers door or door frame on a little sticker. If it is not then it may be in the owners manual. If it can't be found in those places then go by whats on the tire (which will prob. be max 44 psi).

There are two possible things to check.The first being the ignition control module,and the other being the crankshaft position sensor.

perhaps the idle air control valve needs cleaning

Did you check earth connection of electric system?

any gm olds , buick caddy, pont, 4speed auto up to 1991 u just got make sure theyre not computer controlled some 91 are n some aint stay away from 84 to 88 they had failures it doesnt really matter about engine size as along its same transmission

REplace fan control module, purchase car repair book on your model and locate it. Common problem, fan could also oscillate in speed at times.