There are a number of things to look out for when buying a Fourth Generation Z Car (90+) . Check these Technical Service Bulletins (TSO's) Then the following items come to mind also:
1. Avoid very early production cars. Turbo models produced prior to 1/90 and normally aspirated cars produced before 7/90 may have problems with defective valves. The valves may unscrew themselves from the head causing a loss of compression and a rough idle. If you run across a nice car that is on the border, check the engine number to be sure. Turbo cars with engine numbers below 619550 and normally aspirated cars with engine numbers below 777599 may be subject to this problem. (check the data tags rivited to the drivers door jamb, and under the hood for date of manufacture and engine serial numbers)
2. Pay a little extra to get a low mileage car. They are not much more expensive and are much less likely to need repairs.
3. Take the car to a knowledgeable INDEPENDENT auto shop that specializes in late model Z-cars. DO NOT TAKE IT TO A DEALER! I'm sure someone on "The Z Car List" can recommend one in your area.
4. Take the car to a knowledgeable paint and body shop. Make sure the car hasn't been wrecked. Also, make sure that any subsequent paint work has been done properly. The STOCK PEARL COAT is extremely hard to match in many cases - especially the Pearl Yellow. Again, someone on the list can probably recommend a good shop in your area. This is the one thing I didn't do and wish I had done. My car apparently had paint damage on one side that I failed to detect. To match the pearl coat properly, I had to paint 2/3 of the car and pay about $3K.
5. Make sure the clutch bearings aren't making alot of noise. They can make a little noise for 30K miles or more. But alot of noise signals an upcoming clutch replacement, $400-$500. If not abused, the clutch in a ZXTT can last around 70K miles. Quite good for a 300-400HP turbo car.
6. Check out the brakes carefully. The pads will probably only last 30-40K miles. If you replace them with the Stillen Hi-Metal pads, they will last much longer and stop even better. Make sure the rotors aren't warped. That was one of the few prevalent problems on early model ZXTTs. Somehow, mine were not warped and have never been replaced - despite 53K miles and fairly heavy braking. Only have a knowledgeable shop turn the rotors. They can be damaged easily causing warping in short order. Warped rotors will cause the steering wheel to shake and/or the break pedal to pulse...
7. It seems like all Nissan alternators are disposable at about 50K miles. Expect it, budget $250. If someone wants to charge you more, tell them to take a hike.
8. There was one recall - an ignition system power unit. Nissan will replace it for free. Apparently, if it goes bad, the car can stall and won't start again.
9. If you hear an annoying squeak from the front of the engine when the car is cold, its the timing belt tensioner. If it bugs you, buy another car or plan to change the timing belt early, $500 (including the tensioner, $250 without). The timing belt only needs to be changed at 60K miles. But, you have to take the timing belt off to replace the tensioner. It won't hurt to wait, it just makes an annoying noise for 5 minutes or so each time you start it. Nothing is actually broken.
Also, don't let a dealer tell you that the timing belt needs to be changed at 48 months OR 60K miles. Tell them to read the manual CAREFULLY! It says 60K miles ONLY - NOT 48 months.
10. Make sure that the car has the upgraded valve springs. They will make a tapping noise after a while on real early '90 ZXTTs - those manufactured in '89 and very early '90. No damage will be done before the first 60K miles. But, you should replace them when the timing belt is changed. It will cost you an extra $2 (not a typo - they're cheap).
11. If the turn signal blinkers blink at a high rate occassionally (usually just on one side), check the ground on the side that is blinking too fast. It can short out and may even cause it to stop blinking. An electrical shop can redo the ground for about $25.
12. The brake master cylinder on '90-'91 cars will begin leaking at around 40-50K miles. It costs about $200 to replace. The new part is redesigned and is supposed to last much longer. If a car you like has any of these problems, tell the seller you will pay $XXX less the cost to repair the items. That's what I did. The seller had no problem with it once I had my mechanic verify the problems I noted.
I would highly recommend the ZXTT. It is reliable, well built, and a blast to drive. It has a dual personality. On days when Iwant to relax, I put the adjustible shocks in "touring mode" and drive it like a Lexus SC400 with a 5-speed. On days I want to cut loose, I put the shocks in "sport mode" (there really is a HUGE difference) and drive it like a twin turbo RX-7 (Porshe if you upgrade the engine, 400HP is very inexpensive with these cars).
I have only one warning, if you buy a ZXTT, drive it like a granny for a little while and ease into speed racer mode. In first and second gear, power induced oversteer can really sneak up on you. Until you get used to the turbos kicking in, you can spin it real easily. After you get used to it, you can hang the tail out and act like Steve McQueen in "Bullit."