Barebones Nissan EFI

[alsil]

I posted this in Fuel delivery but realized that it's not JUST about that, more of a general thing, so here goes.

What is the bare minimum you need to have installed for the Nissan EFI to work?

I'm guessing it's at LEAST these components:

- Intake

- Injectors

- Throttle body

- MAF sensor (or is it SD?)

- EFI tank and fuel lines, fuel pump

- Fuel pressure regulator (is that on the rail?)

- O2 sensor

- Computer and harness

- Distributor

 

I am thinking about putting this on an L24, but I seem to remember there being a difference between the 2 heads, that you could put the carb manifolds on an L28 head, but not the EFi intake onto an L24...are the heads cut at the intake ports for injectors on the top?

 

With this setup correctly, am I looking at it being more efficient than the Su's, better gas mileage, etc? seems like it would be, more controlled mixture, etc.

 

I figure that most of the pieces I could pick up at the pick n pull or something, so as long as I get good parts, it would be a solid system.

 

I want to bare bones also since 1. I don't need to smog a '73, 2. the less to install, the less that can go wrong. This needs to be a reliable setup that gets good gas mileage since it would be my daily driver, 37 miles each way.

 

Opinions?

[savageskaterkid]

the stock Z's didn't have an o2 sensor IIRC, except for the turbo versions.

 

Megasquirt is pretty cheap if you think about it, known to make more power and gas mileage.

[naviathan]

To answer your questions:

Yes you've listed everything that should be necessary except for the ECU. Some model of the Z didn't have O2 sensors. The MAF is actually the AFM (Air Flow Meter) and obviously you'll need the intake to go with the throttle body. In addition you'll need a large fuel feed line. IIRC the 240Z feed line is too small for EFI. You'll also need a high pressure fuel pump and EFI rated filter. Yes the pressure regulator is on the rail, but it's also a seperate piece that can be replaced.

 

As for the head difference, yes you would have to cut injector holes into the top of the intake ports.

 

If you are looking for something better than the SUs and more efficient, go with the MegaSquirt EFI setup as the stock Z setup isn't much more than an electronic carburator.

[RTz]

Some model of the Z didn't have O2 sensors.

 

No statebound S30's got an O2.

 

In addition you'll need a large fuel feed line.

 

5/16".

 

 

As for the head difference, yes you would have to cut injector holes into the top of the intake ports.

 

Its not just the injector ports... the bolt pattern is different.

 

 

...as the stock Z setup isn't much more than an electronic carburator.

 

Loosely speaking, you could say that about any EFI system

 

 

This '78 EFI schematic may help, Alsil...

 

 

 

One thing to note is that it uses an oil pressure switch for the fuel pump. '75 and '76 used a switch integral to the AFM, '77 and '78 use a specific oil pressure switch.

 

If you're truly looking for "Barebones", in most cases, you can delete the cold start valve, thermo-time, and altitude switch.... and if you're really bent, the air regulator can go as well (fast idle).

 

As I mentioned in your crosspost, you'd probably be better off with a Maxima system.

[alsil]

Wow Ron that's a lot of help. That looks a lot simpler than I thought. If that's for the earlier ones, then I guess the EFI Z's I've seen must have been S130's, because I remember there being a LOT more to it, and piles of vacuum hoses.

 

Yea, I thought about the Maxima setup. You may be right that's a better solution. They had L24's, after all.

 

But if the above is all there's to it, seems like finding an L28 and all the parts is all I really need to do. I can live with the carbs for a while. There are Flat-tops in the car right now, but there are another 2 sets of round-tops, so if the Flat-tops crap out I can always swap 'em....problem becomes sync'ing them up, was never good at it.

[zcar?]

the diagram that Ron posted is very helpfull, and so is a full car diagram, thats what i used when i put my l28 in my suzuki samurai. i diddnt have a factory service book if you have one thats the best book ever (i now have one). it really only takes about 4 wires to make the motor run, and mine starts up and will run all day till it runs out of gas. if i were to do it again i would go megasquirt, i think that it is easier to work. good luck

Jeremy

[Tony D]

Wow Ron that's a lot of help. That looks a lot simpler than I thought. If that's for the earlier ones, then I guess the EFI Z's I've seen must have been S130's, because I remember there being a LOT more to it, and piles of vacuum hoses.

 

The only difference is that S130's after 81 had an O2 sensor.

Turbos had some more vacuum lines to operate some vaccum operated valves, but in Europe they had the same diagram as above! No O2 feedback, just plain programmed fueling.

 

People want to make it much harder than what it really is, and even to this day, when you distill it the componenets are still the same, even for standalones. if you understand the original Bosch System in the photo, you can understand them all, as the inputs don't change, only the way they process some of the signals (MAP versus AFM versus MAF for example. All do the same thing, just in a different way...)

[Daeron]

The only difference is that S130's after 81 had an O2 sensor.

Turbos had some more vacuum lines to operate some vaccum operated valves, but in Europe they had the same diagram as above! No O2 feedback, just plain programmed fueling.

 

People want to make it much harder than what it really is, and even to this day, when you distill it the componenets are still the same, even for standalones. if you understand the original Bosch System in the photo, you can understand them all, as the inputs don't change, only the way they process some of the signals (MAP versus AFM versus MAF for example. All do the same thing, just in a different way...)

 

That is the truest post i think I have ever read of TonyD's.. It is all only complex while you continue to look at it as one big "thing;" break it down into sub-systems and its all wonderfully simplified. That is why repair manuals are written the way they are; not many of them are trying to go to the effort of educating you, though, so the end effect is not that of teaching you how the car works, it is that of helping you get it running again.

[spacecase70]

just a thought, and to add my two cent's worth, the stock FI is a standalone system. just remove the wire harness out of the drivers side of the donar vehicle(75-78 280Z) along with all the components you have mentioned and make sure all connections are clean and tight. and you shouldent have much problems. buy a new intake/exhaust gasket , put it against the head and make holes where there arent in the head, just make sure they are strait, then use a die grinder to make the notches in the intake ports at a 54degree angle so the fuel will flow right to the intake valves. i cannot stress the importance of haveing a good clean and tight electrical connections, o the ghost of my car may come to haunt you, MUHAHAHA!

[Tony D]

just a thought, and to add my two cent's worth, the stock FI is a standalone system. just remove the wire harness out of the drivers side of the donar vehicle(75-78 280Z) along with all the components you have mentioned and make sure all connections are clean and tight. and you shouldent have much problems.

 

 

The funny thing is when I was working on Corvairs in the 70's and 80's THE conversion for drivability was to take and do EXACTLY that! if you get an issue of the Corsa Technical Articles, you will find DETAILED instructions on how to adapt the 'simple Datsun 280Z fuel injection' to your 140HP Corvair!

 

The system does not care what it's on, just as long as it's relatively the same displacement, it runs just fine. I converted several Corvairs to EFI for people running them in the winter just because they wanted the better fuel economy and cold starting abilities of the system. I always wanted to do a Turbo Conversion simply because of the T3's wastegate and inherent drivability... But standalones came out that were cheaper---and the effort was judged useless on such a moot point.

 

Though nowadays when someone says "standalone" they aren't really referring to the ability of the system to be independently removed form the vehicle, but rather to a system that is universal and easily programmed to adapt to any engine, regardless of size.

 

No matter which way you slice it, the Datsun EFI will only work in a limited range of engine operational sizes before serious tweaking is required.

 

One thing that was interesting was that Datsun was still supporting those cars then, so one of my customers took his Corvair (while on the road) to the Datsun Dealership in Saginaw Michigan one time to get something checked out... They said 'we don't service GM's here' but when they saw the engine, they about crapped! Apparently they took photos, and forwarded them to the Regional Office for Datsun and Nissan North America. I found that funny. And one of the technicians there took a little while figuring out where everything was, and did his EFI Checks according to Datsun Methodology---and replaced a sensor...away my customer went! There are people that throw up roadblocks because the information doesn't fit in the box, and there are some that realize that regardless of the packaging, the content is the same no matter what!