I recently started having an issue with my power steering. It started off about a week ago when i was backing out of my garage. The power steeri g just went out on me. I drove it to work and after about 15 mins of riding the power steering came back. It stayed fine for several days and now the power steering goes in and out constantly with no rhyme or reason. It will stay on for different lengths of time and it will vary in length of time that it stays out. I just had new power steering pump installed amd new hoses but same problem. Could it be the power steering pressure switch? Is that the best place for me to start? I have read about the speed sensor as well but my speedo seems to be working fine?? Is there a way to test the pressure switch?

I don't think the NAs use the speed information for power steering, because they don't have HICAS. Regardless, just because your speedometer works doesn't mean ECU is getting your speed reading. The signal effectively comes from the speed sensor, to the gauge cluster, and then it gets changed into a digital signal and sent to the ECU (and/or HICAS in equipped vehicles). An easy way to check this is to get a Consult connector and run free ECU Talk software to see if the ECU is returning a speed signal. Other than that, I'm not familiar with the pressure switch.

Have you added any fluid to it? or do you know if anyone else has? if so, what kind of fluid did you put in it?

It's also possible you have a worn/loose steering coupler

So i can forget about speed sensor as being a possible cause of my problems? The article that i read did not state that the N/A's dont use the speed info

My z has had a big week last week, my brother and i did our first plenum pull. I wasnt planning on it but once we started finding leaks we traced one leak to the valve covers. That was a serious pain in the a**!! Now i know why evryone charges so much to work on the Z!! We started with the intentions of doing the 120k timing kit. I had some leaking cam seals and crank seal! Every hose we touched crunmbled in our hands and every connector fell apart! What i thought was going to be a $300 job quickly turned into $1200 in parts at my brother's cost and two days of labor. My brother owns a garage and has been a mechanic for 20 years. He said that the plenum pull was one of the most difficult jobs he has done. I ended up replaceing all pulleys, belts, seals, coils, plugs, injectors, timing belt, water pump, pcv valves and hoses, a bunch of vacuum lines, all fuel lines, radiator hoses, brake booster hoses, i decided to go with all silicone hoses from Z1! We also deleted the coolant hoses under the upper plenum After we put evrything back together and ran it for a while the power steering pump started leaking, ended up putting a new pump in as well. New hoses for power steering as well. I still dont have functioning power steering as of today. It seems like at low speeds i dont have any power steering but at higher speeds it seems to come back? I am gonna restore my z completley so i want power steering but my brother says that i shouldnt waste anymore money trying to remedy the issue. Over all the car runs great and has no leaks. I also,installed a bunch of cosmetic goodies like new leather trim with white stitching. Looks great. Clear corner lights and side markers. I removed the carpet and seats and pressure washed them!! They look new now! Lol. I have also had a new windshield and rear hatch glass installed while we worked on the engine! I repainted all window trim amd hatch trim while the glass was out. I will post some pics soon. I almost forget the HID lights that i installed. Fog and high/low beams! All thats left now is some leather seat covers.

Back to,power steering issue, while the car was up on racks i checked the steering knuckle assembly and there were no issues there. My rack looks to be on the way out though. Boots are torn and seals are weaping! I doubt that this is the cause of my issue tho. As for the fluid in the power steering system, it was filled with ps fluid by the previous owner. I found an empty bottle of it in the hatch! I filled the new system with atf! Any help would be appreciated. I guess i can always start replacing components but that can be expensive and i would rather fix only whats wrong with power steering. Sorry for the lengthy post but i wanted to be complete. Thanks

I just wanted to update my progress in tracking down my ps issue. I spent most of the morning under my z check electrical connections on my steering solenoid and the rack in general. I cleaned the solenoid connector even tho it looked good, applied dielectric grease and reconnected. No wires were crimped or cut. I testdripse the car after cleaning solenoid connection and there was no change. I decided to pull the ecu and check out the ps control module. It looked clean and in order but I cleaned up connection and plugged it back in. Test drove the car and ps is back!! Well for about 3 miles. When it went out again I pulled over and tapped on the steering module and it came right back. Did that one more time about 30 miles later and it has worked since. I assume the module is bad since I can tap on it and it works for a while. I am just happy to have possibly cleared up
My issue with a new module. Got one from another 96 NA on fleabay for 40 shipped. I will let ya know if it ends up a permanent fix. I will consider that lucky since the other components of the rack and solenoid are so freakin expensive!

Any updates, did the new computer solve your steering issues?

Yes, the N/A does use speed info. I had the same issue as OP. After getting the speedo refurbished (some connections can become loose over time), it was tracked down to a faulty power steering control module ecu, which was overheating. $49 used.