Is power steering pressure/circuit tied into PCM"s fuel control on 97 chevy exp

Power steering input is an input to the PCM but only to raise the idle speed when the steering pump puts "load" on the engine. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online It could be many things, unfortunately and without experiencing the problem first hand or being able to do some basic diagnostic tests its hard to say.