New to site, I just bought a 90 300zx TT

[Sallion55]

Hi there, as I said I am new to this site and I just bought a 1990 300zx TT and it is lhd. It has 147000km on the body, the engine was rebuilt at 122km, there was a oem clutch and transmission put it and a lightened flywheel. It has an aftermarket true dual exhaust. It is white on the exterior and it has a white and black leather trim kit on the interior. There is a boost gauge and a air to fuel ratio gauge. I am mechanically interested I am on the waiting list for schooling as an automotive technition. I had a few questions concerning my car.

1: when it cold starts sometimes the rpm bobs between 100-900rpm, and almost cuts out

2: The car seems to idle lean, when I'm driving it seems to be fine and in stoich, and when I'm pinning it it just goes into rich, so I was wondering if it idling lean is bad and what I can do to fix it

3: when in 2nd and 4th gear, I can feel constant rubbing against the shifter, it is pretty light and it doesn't sound or feel like grinding but I could be wrong. When I'm standing still it's fine, and you don't feel the whole shifter shake but you can feel the vibration come from lower and you can slightly hear it.

4; I know fuel injectors are a common thing that go wrong in these cars so I was going to get new ones but which brand, and which cc of injectors should I get? I was thinking 555cc but I don't know what is best.


I don't want to make my car stupidly fast I love it as it is, I would be fine with making it slightly faster but the main thing I am interested in is keeping this car well maintained. I want to keep it in good Dailey driver condition. I am not going to winter drive it obviously the winters here are harsh but I want to keep this car for the rest of my life if I can so please help me and tell me maintence and other things to keep my z32 running in tip top condition

Thank you for your time!

[NolimitZ32]

Welcome to NICO and congrats on the purchase.

I'll answer #3 real quick: you likely have an aftermarket shifter from one of the lower quality manufacturers and it is rubbing on your driveshaft. Get the car on ramps and have a look at the DS where the bottom of the shifter is, you will likely see a light ring rubbed all the way around the DS. I'll drop back by if I have a chance tonight and expand on the other points.

[Sallion55]

Thank you for your reply! What can I do the stop the rubbing from happening if this is the cause? And I appreciate all the help I can get I have acess to some tools and a decent jack and jack stands but no hoist. I wish to do as much as I can by myself without having to take it in to get serviced.

[DCaff300ZX]

One of the best maintenance items to look at is the electrical connectors, looking for green corrosion. Old vacuum hoses replaced and replacing the PCV hoses and valves is also a good idea, with a good WD-40 blast into the IACV when open never a bad idea at any time as they often get sticky which cause idle issues such as you mentioned in #1, either from that or also corroded connector issues.
Preventative maintenance is good in all engine control areas, and brake upgrades are also common. Be VERY careful with modifications due to the Z32 being finicky in several ways often due to proprietary parts.
Good Luck!

[NolimitZ32]

The only way to permanently heal the rubbing if the issue is a low quality shifter is to replace it with a factory unit or a high quality AM piece. The way that a short throw shifter makes the throw short is by extending the bottom portion of the actual shifter to make the top travel less, some of the shifters end up being just a tad too long. Another way is to try the solid shifter mount (forgot who its made by) this is may remedy your issue if there is a small amount of sag in the rubber piece that holds the rear of the shifter assembly. I know its kind of difficult to understand awhat I am saying now but if you get under the can and actually look at the piece you will understand.

[Sallion55]

Thanks for the replies!! I'm doing the pcv valves, spark plugs, fuel filter, and O2 sensor within the next 2 weeks. Hopefully this will fix my lean idling problem. My other problem I have is when my car is idling, it will start to snoke out the exhausts, mainly a white colour and it smells like gas/oil. This ONLY happens when I'm idling standing still, when I drive the car no smoke comes out. I just drove it up to the lake this weekend and it appeared after the 2 hour drive there is no smoke coming out. But when I cold start my car and let it warm up there is defiantly smoke coming out the exhausts, until I start moving and then it is fine, but if I let it sit and idle then it seems to start smoking slightly. Thanks again and I'm looking forward to feedback on this problem, because it's what I want to fix first, the shifter will have to wait for awhile because I don't know how much work/ money I will need to put in to fix the shifter rubbing

[Bigred*]

Does it only smoke a litte on cold start up at idle, or are you saying even when its hot it still smokes at idle..if its just cold start up then goes away that might point to your valve seals, after sitting oil will slowly drip past them and pool up on your valves and pistons and burns off once you start the car, but typically cant leak past them fast enough once the engine is running..

Thi is by far the hardest car ive ever replaced pcv valves on! Theyre even hard to find, on the edges of the intake manifold, theyre on the under side of the manifold pointing towards the firewall, youll want to remove the battery, probably some of the vacuum lines, and on the other side i remived my brake booster and pulled the wire harness out of the way, you can probably do it with out pulling that, but it made it easier for me..be very careful not to over tighten them!! They just need to be snug! In my irritation and lack of visibilty i tightened my first one down all the way so that the nut portion on the pcv valve was flush with my manifold and cracked my manifold! Quickly became my most expensive pcv valve ive ever done, learn from my screw up, good luck!

[Sallion55]

It smokes after running it for awhile as well, only at idle, but wayyyy less when it has been driven. I took it to the lake this weekend (2 hour drive) and it did fine. It wasn't smoking when I got there but I only let it idle for about 2 minutes. So what do you guys think this is and should I just take it in to get checked out, then I can do the work myself once I know the problem for sure, I really want to fix this smoke problem

[nexus08]

My Z would smoke like a mosquito fogger when first started after sitting all day, and then stop about 1/4 mile down the road.

For me it was the PCV valves. Replaced them and it stopped. They must be crudded up again because she is starting to smoke again at startup.