Barefootdan's 280z Build

[Barefootdan]

A little more detail on yesterday:

I started first by draining the fuel tank. The fuel was getting dark, presumably from sitting in the tank for about 6 months, breaking down whatever my cleaning didn't wash out. I was able to pull out about 2 quarts of fuel. From there I headed to the front of the car and drained the fuel rail. I still had 35ish PSI in the line, but cracking open the line I had a nice long hiss of air, followed by a few oz of fuel. So there was definitely a major air pocket up there. New fuel went in, primed the lines, and it started right up 😄

I let the car warm up to start working on the idle. I couldnt get it down below 1200 for the life of me. I placed new vacuum plugs on all fittings, replaced all vacuum lines, and started using starter fluid to find any leaks. Nothing was present. Luckily I found a Youtuber who was encountering the same issue. The BCCD block off plate cant just be placed on. You need to plug one of the holes to not let the air pass through the throttle blade. A quick plug and boom, problem solved! I dialed up the idle to be 800rpm. Set my timing to 12 degrees BTDC. I will probably back this down to 8-10 since I am running a higher compression flat top piston. I can finally clean up my cobbled up wiring job for my fans 😄

I had the car pulled out of the garage during my testing and was tired of pushing it back into the garage. I slapped a plank of wood inside to sit and precariously climb in. Clutch felt great, brakes not so much. But I slowly went into reverse and backed her up into the garage. A very anti climatic first drive of 10 feet...but it was the first time moving under its own power in nearly 30 years! 

I do have a minor leak at the oil pump (I think). I am surprised no rtv was called for in my manual for this gasket. I will do a thin layer and hopefully that will fix it. New oil and a filter will wrap up the engine work. The floor restoration is up next...stay tuned.

[siteunseen]

There's a bcdd hole in front of the throttle blade that has to be filled or blocked to stop the ported vacuum.

Here's something I found real quick. @Captain Obvious is the thinker that helped me.

 

 

[siteunseen]

That wasn't a good choice for "The Thinker", hindsight is a bitch.

Looks more like me sitting on the toilet. The "stinker".

 

[Zed Head]

6 hours ago, Barefootdan said:

I am surprised no rtv was called for in my manual for this gasket.

RTV was new space age stuff back then.

https://www.permatex.com/who-we-are/history/?locale=en_us

[Captain Obvious]

4 hours ago, siteunseen said:

That wasn't a good choice for "The Thinker"

Looks more like me sitting on the toilet. The "stinker".

That all makes sense. Many people do some of their best thinking in that location!   

[Barefootdan]

Hahaha that’s perfect!

[Barefootdan]

Well… the highs are high and the lows are low. Today I changed the oil and retorqued the ARP studs. A few needed about an 1/8th turn to get back into torque but nothing felt odd. 60ftlb per the ARP slip. I ensured I was going in the correct sequence as well. Started up fine and I started to let it warm up. Not even a couple minutes later the idle became strange. Wouldn’t want to rev either. Then the dreaded smoke started coming from the tailpipe. It definitely was not even at operating temp yet. I thought maybe I spilled something and left it at that as I bled the front brakes. I came back to start the car and still smoke. The car is filled with water in the coolant system for reference so no odd smells. I pulled cylinder #6 plug and well….

 

 

I have no idea how this could have happened but I think the head gasket just blew. Someone please tell me there may be another answer but all of my car knowledge points to this 😅 

Edit: first thought is perhaps an air pocket. But I do recall the fitting in the picture blowing off during my first warm up since I forgot the clamp. I cant imagine air getting trapped when that happened, unless it made its way back there...just odd that it happened when the car was not up to temp. Second thought is maybe one of the coolant passages is blocked with gunk? Hard to speculate though without removing the head. Such a bummer, right as it was done! The bright side is that if it is the head gasket, it is a cheap fix and can be done in a day. 

Edited October 6, 2021 by Barefootdan

[Barefootdan]

Took off the valve cover and what in the world!!! And intake rocker jumped on #4. Luckily nothing is scored and the retainer was easily found. 
 

could this be the culprit? Maybe the fuel was building up in the chamber and steaming off? But this would probably have been black smoke? I’m hopeful but doubtful…other thought is the increase in vacuum was pulling oil through the seals causing the smoke. 

 

Edited October 6, 2021 by Barefootdan

[Zed Head]

The smoke could have just been vapors coming back from an open valve.  You'll want to measure cylinder pressure before assuming you have a bad head gasket.  

The thrown rocker arm could happen because of a sticking valve, maybe a tight guide or valve seal.  I'd just keep doing the small things to get it to run correctly and let the parts wear in and see where you end up.  No need for panic.

[Barefootdan]

1 minute ago, Zed Head said:

The smoke could have just been vapors coming back from an open valve.  You'll want to measure cylinder pressure before assuming you have a bad head gasket.  

The thrown rocker arm could happen because of a sticking valve, maybe a tight guide or valve seal.  I'd just keep doing the small things to get it to run correctly and let the parts wear in and see where you end up.  No need for panic.

Thats a relief. Thank you. I was jumping to worst case scenarios and didnt even think of the vapors from an open valve. 
The valve lash of all other cylinders was in spec, so I think it is safe to assume this one was too. I'll keep an eye...or ear 😉 ...out for any strange sounds next time I fire it up. Open headers doesnt make it easy, so that could be my next project in the meantime. 

[Barefootdan]

Fixed the valve and it started right up nice and smooth again. Still smoked for a few minutes but it eventually died off...what a relief! Crisis averted👍

Now back to our regularly scheduled build 😄 

I was able to get the muffle hooked up which helped tremendously with listening for any strange noises. I'll grab some pictures this afternoon. The last piece preventing a spin around the block is brakes. I was able to start bleeding the front but my driver side bleed screw is clogged. Going to soak it or grab a new one if that fails. 

[Patcon]

You can unscrew the bleeder all the way and hand thread a small drill bit in and clean out any gunk that way