New member here with 91 300ZX TT

[Datzxjr]

So my dad passed away recently and he was a big Z car fan, 240Z, 300ZX and a 350Z. The 350Z runs fine, the 240Z is completely dismantled with a rebuilt engine and who knows what other new parts are hidden... lol. My big problem is the 300ZX. It's been sitting for probably 5 years. I don't know what all he's done (he bought it new). I know he did the exhaust, turbo timer, some HKS stuff and possibly a chip or tuner. I tried to start it last night and it would crank but not start or even try to fire. A couple things I noticed, when I turn the ignition on I would expect the gauge needles to move (reset) but that didn't happen. I'm wondering if something isn't getting a signal to allow it to start? I didn't have much time to diagnose much, but I'm thinking to check and make sure the fuel pump is working first. What are your thoughts?

Thanks!
datzxjr

[Datzxjr]

update, found no fuel pressure. Checked power to the pump and got a initial 12v, then check resistance on the pump motor and it's open. Also found the fuel level sensor stuck down which makes sense since the gauge reads empty...1 OEM pump on the way!

[Woodnutz78]

Hey man... first, so sorry for your loss. Hope you and the family are doing alright... or as alright as possible.

For the gauges moving - if you're talking about a sweep where the needle sweeps through the full range, they don't do that. Aside from that, I THINK the only one that would move when you key-on would be the temp gauge... and if it's cold, it may not move anyway.

If it's been sitting for that long, at a minimum, I'd dump the tank and put some fresh 91/93 in it first. Maybe he had sta-bil in it, but I'd still be worried about the system being pretty gummed up from being static for that long. It's pretty easy to hear the fuel pump prime when you key-on. If you don't hear anything, that's at least a starting point.

Furthermore, unless you know that the timing belt was changed not too far beyond that 5 years, that's a must-do as well. Otherwise, you run the risk of ruining the engine. It's an interference engine, meaning at different points in time, the valves and pistons occupy the some of the same physical space. While there's a mileage interval on the belt (not a time interval), 5 years of it not being run isn't good for that material and I'd change that before attempting to start again. Pistons hitting valves = trashed engine.

Where are you located? If you're not ready to jump into the rabbit hole of Z32 life, I can make recommendations on who to take the car to. It needs to go to someone who truly knows Z32s - they're a different animal. I've been learning continuously since I got mine in 2018.

[Datzxjr]

Thanks Woodnutz, I was checking it out yesterday and the gauges seem to work, the only gauge that moved with the ignition on was the boost gauge. And now I know why the fuel gauge didn't.. He did all the work on the car himself and I know the timing belt was changed possibly twice. I will drain the fuel tank before replacing the fuel pump. I'm in south florida and I also do most of my auto repair and diagnosing. It is hard to find a trustworthy shop, especially down here. If anybody's gunna F up my car it will be me! lol

[Woodnutz78]

Sure thing... looks like you're on the right track. I have the same exact philosophy with my Z - that, and I enjoy learning about it, too. Hopefully the new pump gets you started. I'll echo the TB change again. It's insurance, and if you can follow instructions to the letter, it's really not that tough of a job. If you're not familiar with the car, I know there's a way on this site to get the factory service manual, and there's also a lot of technical writeups on twinturbo.net. If you need parts, get with Bernie Bilski - also on tt.net, but I know he does facebook, too. He's arguably the top mechanic for the Z32 and he's got tons of parts. Good luck!

[Datzxjr]

Cool, thanks for the tips!

[NolimitZ32]

For fuel pump, try powering it direct bypassing the FPCU, these are a known to go bad often enough.
For timing belt, if it has sat for 5 years at least check the physical condition, heat does nasty things to rubber.
For no start, first confirm spark, then confirm signal to injectors. Pull the CPS on the left head, keep plugged in, turn by hand while listening for injector clicks.
If all above get you nowhere do a leakdown and compression tests.

[Datzxjr]

Maybe I should've put this in the tech section ... anyways I have a update!

Nolimit32, the pump motor had no circuit so it wouldn't have ran. After I threw it out i should have tapped it with a hammer a couple time and tested it... probably had contamination on the commutator and brushes...

I installed a OEM pump and replaced the filter, it still had the old gas (maybe 2-3 gallons) so I added a couple fresher gas to help. I know I should've drained it, but it has a flat rear tire, had no drain pan and i was lazy. lol So I turned the ignition on a few seconds to prime then cranked it for 5 or so seconds and it started up. I was very happy!!
Ran like s*** though... Couple of things I thought about what it could be, was a misfire, bad plug or coil pack, vacuum leak, bad gas ( ) , maybe timing. So, I let it run till it got up to temperature. During this time, it idled around 1200-1400, that's when I thought it might be a vacuum leak. It ran really rough. It did come down to around 600-800, then it loped from like 800 to near stall and back. It never did stall. I did notice a liquid coming from the exhaust, it didn't smell like gas but looked like it. Maybe the old fuel blowing by. So after that I closed it up and went home. My next step is to drain the tank, put in new fuel and try it again. Also, I'm going to check for spark on all plugs and want to make sure all the injectors are working.

NoLimitZ32, what is the CPS? I'm guessing I need to have the ignition on to test? Is there a certain position it needs to be put back in at?

Looking forward to get the beast running

[NolimitZ32]

CPS is cam position sensor. The silver round thing on the front of the left head. Ignition on but not running. The stem only fits one way, mark the bolt locations on the casing so you can set it back where it was once done.

[Woodnutz78]

For what it’s worth, it’s also referred to as a CAS (cam angle sensor) - just to make sure you don’t get sideways while looking around online. Also, be sure to have a timing light, even if you mark it as you should, you’re guaranteed it’ll be off a little… and probably good to check regardless.

Using a long screwdriver or similar (I have a long 1/4 extension that I use), listen to each injector for clear, consistent tapping. Being a ‘91 w/ the old-style injectors, strong chance several if not all are internally corroded. If you hear sputtering or inconsistent tapping/clicking, they’ll need replaced. I bought a new-style retrofit kit from Bernie a few years back to clear my misfire.

Keep us posted!

[NolimitZ32]

CAS is the correct term in Z32 world. I've been working on too many other cars in the recent past.