Help! Cold start valve has no place to connect to fuel rail

[ntownsen]

OK has anyone else seen this? I bought a 77 280z that someone had already started a rebuild so I have no reference on how things 'used to be'. I'm starting reassembly and can't figure out how the cold start valve attaches to the fuel rail. This fuel rail is solid piping except where the regulator assembly mounts. I have two other z's to compare to and neither have this configuration. Ideas? I'm stuck.

[EuroDat]

Do you have the FSM (Factory Service Manual) and the Fuel Injection Supplement? You can download them here XenonS30. The Fuel injection supplement in down in the other guides section. It has some great diagrams showing where things are located and how they are connecte.

From your discription sound like you have an aftermarket fuel rail, maybe the Pallnet fuel rail and may need to be drilled for the CSV fitting.

Here is a thread from rossiz with some good photos of the fuel rail and CSV. See the first post http://www.classiczcars.com/forums/open-s30-z-discussions/52515-refreshing-intake.html

Chas

Edited August 21, 2014 by EuroDat
Link fix

[siteunseen]

I've got an aluminium rail similar to those Pallnet makes. I ran the CSV hose off a "T" at the back. One side goes to the FPR, the other to the CSV.

[ntownsen]

I do have the FSM and don't see anything like it. It looks just like the 77 fuel rail only it does not have the nipple for the cold start to connect. Also noticed last night that the pressure regulator only has two fuel and one vacuum connection instead of the typical 3-1 and is bolted to the rail instead of hanging loose. This is a late month '77. Could this be a transition model and have a fuel rail off a turbo or zx?

I doubt it’s an aftermarket because it has the whole spaghetti coiling pipe thing going on and I would assume going to aftermarket would be to clean things up. Also I have met the original owner and he was a "take it to the shop guy". The subsequent owner was focused on bodywork since the car was running. He had just started working on rebuilding the engine when he ran out of money and enthusiasm. By all accounts the parts I have were on the car when it ran last, but I just don't see anything "standard" with this setup. What kind of mutant do I have on my hands and what do I do about it? Thinking of pulling the rail off of a local '76 and being done with it, but the stubborn side of me wants to figure this out.

Edited August 21, 2014 by ntownsen
Spelling

[siteunseen]

The '78 has a 2 fuel, 1 inlet the other's the return line, and 1 vacuum nipple. Some people don't use the CSV. Maybe it's been deleted?

Put up a picture so we can see.

here's a '78 FPR, http://www.rockauto.com/catalog/moreinfo.php?pk=47132&cc=1209260

and a '77s, http://www.rockauto.com/catalog/moreinfo.php?pk=46963&cc=1209248

Does the driver's door plate date say it's a '77? Usually September is when they change to the next year on the title.

Edited August 21, 2014 by siteunseen

[Zed Head]

This fuel rail is solid piping except where the regulator assembly mounts.

1977 was still using the multi-piece rail with fuel hose to connect the pieces. Solid would be 1978 Z or 79-83 ZX. Your description of the regulator says 78 or ZX also.

It's been known for people to braze a patch over the CSV hole after they cut off the tube. It's described in a few posts around the internet.

The CSV is probably overkill fuel enrichment for anybody not living in Canada or the northernmost states of the USA. You might need it for a few days in the wintertime in Cashmere but worst-case you'll probably just need a few extra revolutions of the engine before it starts. The piping that you're missing is generally in the way,and the CSV injector is one more place to have a leak, that's why many people remove it. I cut mine off and capped the stub with a 5/16" compression fitting, when I had a stock rail.

So now you can have it figured out and still leave it off. Best of both...

[siteunseen]

Where you been?

[ntownsen]

My fuel rail clearly looks like a modified 78 as zed head described.

Mystery solved! We have about 3 months of cold weather so I'm leaning toward replacing with the 76 fuel rail and keeping the CSV.

Thanks for all your help in identifying this rail and suggestions.

Edited August 22, 2014 by ntownsen

[S30Driver]

Lots of changes, N42 intake instead of the stock N47.

The fuel pressure reg. vacuum line connects to the port that is to the right & below the fpr.

[Zed Head]

I think that 77 might have still used the N42 head and intake. The N47 change was mid 77 and/or 78. I don't really see a patch in that picture but it might be there. It's possible that Nissan made a variation for later L6's, like the L24E. Who knows.

The 76 parts would work to get the CSV back in action. You might try driving up to Mount Rainier for a night though to see if you really need it. Make sure that you use EFI rated hose to connect the rail together.

[Zed Head]

Where you been?

Me? I ran out of words... Had to reload.

[ntownsen]

I took the fuel pressure regulator vacuum hose off for the picture and I am definitely using EFI hoses!

The N42 intake change was my hair-brained idea (off the same '76 I got the fuel rail). The EGR pipes were severely damaged and rusted to the N47 intake. After contemplating the cost of said pipes (the small one being impossible to even find) and potential machining cost to repair the broken bolts I was bound to cause, I decided to use what I had and scrap the EGR, BPT, BCCD. I just used the intake manifold I already had sitting on my garage floor. It did mean having to plug the EGR hole in the exhaust manifold but at least this way if I eventually get all those parts assembled I can put it back to "stock" at some point with relative ease ( ... nothing is easy with this car).

I guess I'm starting to get impatient with this car. The engine has been sitting on my garage floor for three weeks as I tinker with putting it all back together ... one step forward to find 3 other problems. Now I just want to get the engine back in and on the road!