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FI Conversion from Carb - 77 620

Posted: Sun Feb 21, 2016 2:54 pm
by METSystem
Summer is going to be here quickly! Last year I got myself injured and spent the summer in casts, surgical boots and crutches for almost the whole year, so the Datsun never got worked on. . . Watching "Fast n Loud" recently I saw they had a bolt on aftermarket fuel injection kit they put on a 69 or 70 Buick Riviera and the thought hit me. . . 'The carb on the Datsun is shot, and a new Weber is spendy, and a used Weber is chancy, if I'm going to spend the multiple bills on a Weber, plus the tune in time. . . What in the heck would it take to do a fuel injection change over on the 77 L20B in my 620?'

Back in the day, I remember that the Japanese container load engines that were being brought over from Japan had FI over there way way back. But, the brain boxes were never accompanied with the motors and harnesses had been cut as well. So, there are FI L20B's in the world, so it's not impossible.

So, what are the thoughts on the pending research and process to make this a go?

Re: FI Conversion from Carb - 77 620

Posted: Sun Feb 21, 2016 3:19 pm
by devilsbullet
The guys from roadkill did this to a 69? Buick skylark goon. Actually seemed fairly straight forward, though considering who was doing it it's probably not as much as it looked. I'd say no harm looking into it, could call a manufacturer(can't remember who made theirs) and ask them.

Re: FI Conversion from Carb - 77 620

Posted: Sun Feb 21, 2016 3:39 pm
by DRIVEN
Is cost a concern?

Simplicity?

Re: FI Conversion from Carb - 77 620

Posted: Sun Feb 21, 2016 4:06 pm
by wayno
Them Fuel Injection manifolds are rare, there are a few around though, but the ones for sale are $500.00 or more depending on how complete.
Some guys make one out of a 6 cylinder Zcar manifold cut down to 4 cylinders, that would likely be the easiest way if your looking to save some money.
Most use a stand alone mini harness/ECU to run everything either bought or made from a 4 cylinder like the EFI 200SX.
It's a lot of work, a new Weber will cost you less money, save you time, and create fewer headaches.

Re: FI Conversion from Carb - 77 620

Posted: Sun Feb 21, 2016 4:18 pm
by Laecaon
If you are interested in the simplest way, go throttlebody injection. Make an adapter for the throttle body to your manifold. Source all of this from a similar displacement motor.

Its not performance, but its simple (if you find a setup with less vacuum lines).

This is basically what you saw on TV, a glorified TBI setup. What we think of now because it is way more common place, and more efficient, is multi port injection.

Re: FI Conversion from Carb - 77 620

Posted: Sun Feb 21, 2016 7:59 pm
by DRIVEN
^^^This^^^

I'd source parts from an early ('82-'86?) Cavalier or like platform with a 2.0L. Since you can run a matchbox distributor with a GM HEI module, I would think that one would work as a trigger. Aside from the throttle body assembly, you would need the MAP sensor, O2 sensor and coolant temp sensor.
The harness is pretty basic and the ECM is about the size of a Nissan unit. Another possible option would be a Holley Pro-Jection controller since all the other components are GM based.

As Wayno said, a new Weber would be cheaper and easier.

Re: FI Conversion from Carb - 77 620

Posted: Sun Feb 21, 2016 8:05 pm
by devilsbullet
they start putting it in at the 19 minute mark. Considering they're putting it in in a parking lot with 25 ish degree Temps, can't be too difficult so long as they have a kit to fit an l20. Company is atomic I believe

Re: FI Conversion from Carb - 77 620

Posted: Sun Feb 21, 2016 8:11 pm
by DRIVEN
MSD makes the Atomic systems. Haven't seen one for a small engine before.

Re: FI Conversion from Carb - 77 620

Posted: Tue Feb 23, 2016 12:07 pm
by METSystem
DRIVEN ยป Sun Feb 21, 2016 9:11 pm wrote:MSD makes the Atomic systems. Haven't seen one for a small engine before.
Well, when the time arrives, I'll probably find out, sit back and laugh at the folly of it all! But. . . it'd be cool as hell to have it installed and working well! ;)

Re: FI Conversion from Carb - 77 620

Posted: Tue Feb 23, 2016 12:31 pm
by DRIVEN
I wish someone would. I'd like to see how it works out. EFI is a nice addition to any carbureted Datsun.