New member, new 300zx.No start, possible blown engine? Video

[awol_G]

Well hello.
I've loved Nissan since my 1st Infiniti g20 ~12 years ago. IMO the most undervalued cars of the 90's.
I actually bought my 1st z today, pretty stoked
She is red 92 N/A 300zx auto, very clean body (for 21 years old haha) cloth interior . Obviously I'd prefer a TT manual, but this is my babe now, I'll get pics up soon.
I got her kind of cheap, knowing that she wouldnt start and it could be anything. Guy said he didn't know and it'd been sitting over winter, I'll beleive him I wouldnt drive it in Colorado winter either.
She didn't even have juice in the battery and someone else was already there trying to talk him down. I said F it and gambled, payed his (reasonable imo) asking price... Didnt want to miss out.
Kinda hoping they never got updated PTU, or maybe security system starter disable problem.

Got her towed home and put jumpers on. Got an ugly sound.
I found a vid on youtube w/the exact same sound, its not very encouraging.
[youtube]http://www.youtube.com/watch?v=whlcv41yR68[/youtube]
Mine sounds exactly the same, but I wouldnt say I can really feel the engine trying. I feel very little vibration, I'm hoping simply bad starter.
Has anyone ever heard just a bad starter make that noise?

Maybe its something else, hopefully. Or is that sound basically a seized engine no matter what?

Just any opinions on what next? I was in the process of yanking the starter to replace. Should that be the next step, or something else?
Should I be worried about the PTU,CAS insted?

Hopefully you can tell I searched a bit, I just am a touch frusterated and dont have anyone to bounce ideas off.

EDIT:I've pulled back the timing cover a bit and the timing belt seems well tensioned, also a somewhat worn service sticker for 12,000 miles ago (assuming the tach works).
Hopefully a good sign...

SIDE NOTE: I'm in Denver,CO. Any awesome shops just in case.
I told myself when I bought it that she may be my 1st engine swap. You know N/A to TT, but its overwhelming at the moment haha.
Maybe if she needs swaped just NA for ease, since it is my 1st swap, we'll see...

[Ace2cool]

That sound isn't a seized engine. Possible that the starter solenoid's not engaging the flex plate ring gear, or the ring gear could be broken free of the flexplate, since you already ruled out timing belt. Either way, it doesn't sound like a seized engine. That guy doesn't know what he's talking about.

What you need to do is get a socket and a breaker bar on the crank nut, and try to rotate the engine by hand. If it rotates, then the problem is with your starter. Either the starter itself or the flexplate.

My money's on the starter.

[awol_G]

You're the man Ace!
Exactly what I needed, some encouragement!

I've got the starter splash sheild removed, but no new starter til tomorrow anyways (everythings closed) so I held off to look at videos online haha. Maybe I should have kept working, that vid messed w/me. I would've had the starter off, if this vid didn't get me under the timing cover lol.

I'll get this updated in the morning, and I'll try to get some decent pics too!

[Ace2cool]

Before you yank the starter off, try taking a wrench or a hammer and hitting the solenoid. I've seen the solenoid freeze and not engage, even though the motor was spinning. If this works, then the starter is still bad, cause this is only a "band aid" fix that'll get you to the parts store/home, so it'll still need to be replaced. Good luck!

[t.mcginley.jr]

Yupp, busted starter. It's spinning like mad but not actually moving out to turn the flexplate. And don't worry about the price, I got mine super cheap too haha

[awol_G]

Well today I finally was able to get someone to turn the key while I look around.
Starter engages, flywheel spins, timing belt is turning.
Checked the fuel line, its got pressure.
I dont think its a vacuum issue.

So now I'm thinking spark.
Gonna do more reading on CAS and PTU

[NolimitZ32]

Grats on the purchase. Have fun fixin her brother. She'll be a cruel mistress but so rewarding when you get her running right.

[awol_G]

Checked the ECU, code 55...
I'm trying not to throw $$$ at her blindly.
I really dont know where to go from here.
Keep searching haha...

Cas seems to be almost dead center so I'm doubting more and more a timing issue

[t.mcginley.jr]

Does it have an old or new style PTU?

[awol_G]

Does it have an old or new style PTU?

She has the new version, and it doesnt even seem corroded at all, but I think it may be bad (It was never relocated, and the 2nd version goes bad from the heat occasionally right?)

I can hear the injectors firing so that eliminates the CAS right?
No spark it seems. Kind of frusterated right now, so I took a mile high smoke break and called it a day.
I've got an idea to check the PTU not using resistance, curious what you might think.
I was thinking hook the timing loop wire on the ptu harness to my gun and see if it flashes during start attempt, could this be a decent way to check the PTU?
It seems I'm getting no spark at all, I am almost convinced its PTU (or a bad ground)...

Found a guy on craigslist who has a used, but said to be working v.2 PTU.
Probably snag it from him and see if it works. It would be nice to diagnose the PTU before spending $.
I've seen this thread: dead-cylinder-can-t-figure-out-why-read ... 64452.html,
might have to do that... But I'm hoping the timing gun just doesnt flash, and that should basically indicate the ptu right?

[Ace2cool]

Yeah, or you could just pull the plug and ground it to the plenum while cranking it over with the starter.

[awol_G]

Well update...
I found a J30 PTU at the junkyard, swapped and now spark is happening. I can see it when I ground on the manifold haha.
Still not turning over though.
I'm checking each plug to make sure their wet, made it 1-4 so far, cylinder 1 seems to have a bad injector. The rest of the plugs seem pretty fouled (I've seen worse on cars that start though), but getting wet.
1 bad injector be enough to keep this thing from firing up?
The struggle continues, maybe it jumped a tooth on the timing belt or something. I'm still optimistic the engine is ok at the moment though.
I'm going to do a real fuel pressure test soon, and compression test too.

Any other ideas where to go from here?
Still throwing code 55 (The A-ok code)

[awol_G]

I think I know what killed the PTU.....
Did my cold compression test, 30 psi in cylinder 1....
Didn't even bother checking the other cylinders haha.

I get to start thinking about swaps now I suppose lol

[Ace2cool]

There's no such thing as cold compression. You can only check compression with the engine warmed up. Reason being, the piston rings haven't expanded to fit the cylinder walls as well as when the engine is running. You need a leak down tester if you want to know compression without having the engine running.

Besides, a low compression cylinder won't kill a PTU.

[awol_G]

There's no such thing as cold compression. You can only check compression with the engine warmed up. Reason being, the piston rings haven't expanded to fit the cylinder walls as well as when the engine is running. You need a leak down tester if you want to know compression without having the engine running.

Besides, a low compression cylinder won't kill a PTU.

I like how you keep giving me reason to stay optimistic!
That helps to keep hope alive.

I've heard cold compression tests aren't reliable, but I just was working w/what I have. Maybe thats why i didnt even bother doing the other clyinders, subconscience doing work or something haha.

Perhaps a leak down tester is in my soon to be purchased list.
Is cold compression really completely useless? Is that kind of engine specific or engines in general?
Obviously I'm new to Z's and not a top mechanic. My thinking on the ptu was that engine was overheated causing head gasket failure on cly 1. Ptu being so close to cly 1and radiator might get super hot and fail.
Maybe I am a worst case scenario type, I've watched all the final destination movies lol.

Whatever is going on, eventually will get figured out I think.
I'm going to take some time with her, I'll definitely keep updating as I progress. I can use all the help, opinions, and advice I can get.
Thanks

[Ace2cool]

Lol, that's some imagination there. It's not impossible, but not probable either.

Yeah, leak down test would be the best bet to tell you what's wrong. To my knowledge, there's no good cold compression test. Any engine I've ever worked on, the FSM always says to have the engine at operating temp. I tried it on my 2+2 before I sold her, and the compression jumped nearly 100psi.

You're definitely getting closer to finding the issue. Worst part is not wanting to just throw parts at it.

[awol_G]

You're definitely getting closer to finding the issue. Worst part is not wanting to just throw parts at it.

Why is the worst part not wanting to throw parts at it? I thought generally it was best to diagnose before getting parts.

I need an air compressor for a leak down test huh? Well I have always wanted air tools....

[Ace2cool]

No, I mean if you had unlimited funds, it would be way easier to simply buy all the parts for the ignition system, but that's not really feasible for most of us.