Failed CO emissions - all controls removed - where to start?

[thetwood]

The angle of the picture doesn't help. Originally, it actually was on the return side. That didn't seem right, so I switched it to the feed. It's inline with the filter now, just doesn't look like it in that picture.

[thetwood]

35 minutes ago, siteunseen said:

There it is!  

If you're not careful that timing chain tensioner will ruin your day/week. The cheap plastic ones are very scary to use trust me. If you have some hardwood scraps you can make your own. I will trace around mine and fax it to you then you can make your own. If you get that far let me know. Yep, still have a fax machine.  If YOU don't I will scan and email it to you.

I do not in fact have a fax machine... But if you can email it to me that would be awesome. I have plenty of hardwood scrap here, so could cut one out easy enough.

[Zed Head]

If you're planning to remove the camshaft you might be getting ahead of yourself on the original goal.  Just saying, it's easy to get diverted.  People often start changing things then just get lost with a new set of problems.  One small mistake and you'll be removing the head, then drilling out a broken head bolt, some broken exhaust studs,  Yada yada etc.

[siteunseen]

I think he's wanting to see the writing under the cam sprocket to determine what cam he has. Good to know if you can find it. Aftermarket ones have different valve specs. If I was you I would read up on sprocket holes 1,2 and 3. They can be swapped to make up a tighter chain after wearing. They stretch somehow. 

Blues, er Japanese Racing White's, Tech Tips has a write up on it.

Google "Blues Tech Tips". I'll give the scan a try tomorrow after work. Today is for running my mouth and beers, or vice versa.

Edited September 8, 2019 by siteunseen

[Zed Head]

Still, does it really matter?  If it's a radical cam he'll be able to tell by the loping "cammy" idle.  If it's not radical it probably doesn't matter too much.

I see multiple things happening at the same time.  The path to the disassembled "wish I hadn't done that" engine.

[siteunseen]

That's what I like about you Zed Head, you're Big Picture! I can't see past the end of my nose.

If he's not thinking about changing the cam, and I would not, this would be overkill I guess. You and I have nothing like a 16 year old chomping at the bits to drive a Z so we're a little more methodical after all we've read on this forum. 

@thetwood I would hold off on the cam specs I guess. That was me poking you along and I apologize. It's like putting clean socks on dirty feet. ?

The basic stuff is where your mind should be right now. I think if you set it up like mine it'd be fine (of course).

You'll need a '78 fuel pressure regulator. Those adjustable ones are s h i t.

[Captain Obvious]

It's clearly a OEM Nissan cam, but it's not clear if it's been reground, right?

If I'm understanding correctly, couldn't he just measure the cam base circle in-situ and determine if it's a regrind?

 

[Captain Obvious]

And @thetwood,  You're doing a good job of becoming your own expert.

Good work!  

[Pilgrim]

7 hours ago, Patcon said:

Be very careful removing the cam sprocket. If you let slack into the chain the tensioner will pop out and it will require a lot more disassembly!

Oh God almightly, BE CAREFUL!!!  I did this.  There is a drawing in the manual for a wood wedge that is used to block the chain tensioner from moving when you create slack. The drawing is deceptive - that tensioner is much farther down inside the timing gear cover than you think it is.  I have been in there, and I personally would NOT do that unless I could get a very accurate wedge drawing from someone with a demonstrated working wedge. (I'm delighted that you have a volunteer for this.)

That wedge has to be way down in the timing cover, and it must be tapped into place VERY firmly.   I thought this was a rather trivial deal when I pulled the cam sprocket, but it is NOT. It's a potential huge pain in the arse.

Screw that up, and you'll have to pull the fan, water pump, crank pulley, and timing cover to get at the tensioner. It is VERY difficult to get that timing cover back on with the gaskets oriented properly with the head on the engine.  I gave up and had a professional shop do it. 

Edited September 9, 2019 by Pilgrim

[siteunseen]

19 hours ago, thetwood said:

I do not in fact have a fax machine... But if you can email it to me that would be awesome. I have plenty of hardwood scrap here, so could cut one out easy enough.

Okay, this is going to be a couple of post to hopefully get it right so bear with me.

Here's the scan first off.  It's a pdf file you can print out then cut the shape out to make your tool.  Save it to your computer then open it and PRINT.  I think that'll work?

tensioner tool.pdf

 

 

[siteunseen]

I'll use my phone for part 2, pictures, so hold on...

 

[Pilgrim]

5 minutes ago, siteunseen said:

Okay, this is going to be a couple of post to hopefully get it right so bear with me.

Here's the scan first off.  It's a pdf file you can print out then cut the shape out to make your tool.  Save it to your computer then open it and PRINT.  I think that'll work?

tensioner tool.pdf 490.41 kB · 2 downloads

 

 

FYI...I can't open it or save it. Not sure what's going on.