I put the 86 engine, harness, and cpu in my 79 but i can't get the ignition to work, does the cpu get it's power from the coils, or from the engine harness??? I have a 87 workshop manual that shows a wire that leads from the battery to the cpu it goes through numerous plugs and changes colors quite a few times but it ends up at the cpu, or so i beleive. If i'm right it looks like i can tie into it with one of the plugs from the engine harness that a by the cpu, with a fused 7.5 amp fused line from the battery, does this sound right??? PLEASE HELP https://www.nopistons.com/forums/pub...IR#>/dunno.gif

Sounds like your on the right path.Are your coils getting 12v?what are you using for a pump now?

yah, it goes to the engine harness under the dash i think



mike

ya, the coils are getting 12V from the main relay, and i'm using a walbro 255 inline pump

Cool.Good luck I think mike is right about that power wire.Let us know how it goes.Best of luck making the SA a EFI car.

Thanks at this point in time i need more than luck! I'm going to try that hopefully it warms up a bit, i can't stand working with numb fingers. I'll let you know how it goes.

well i tried to run the hot wire from the battery to the cpu, but it still doesn't work, the coils have 12V but no spark, i'm going to borrow a friends 86 and test each wire that plugs into the cpu with the ignition on to which ones get 12V then if i find any that do where mine doesn't just run one! I hope this works...



asuming i undo the fuses of the ones that i already know where mine has 12V then just look for one that does, maybe i missed something?



I'll be sure to let you know what i find, also i tried another cpu (not the problem)

did you say that you are using a 79 CPU?....or was that a mistake

no 86 engine, harnesses, cpu; in a 79 body

the ignition system on an fc is simple. the cas sends its signal to the ecu, and the ecu sends its signal to the coils, so it can basically only be those 3 things or the wiring in between



mike

simple, ha maybe for the guys in japan that built it all! NO i see what you're saying i believe that the cpu is not getting power or the cas signal is not making to the cpu, or from the cpu to the coils, yes one of the 3, I'll let you know what i figure out.



I'm thinking maybe a black wire yellow tracer, that goes from the main relay to the soenoid resistor for the fuel injectors, or a black wire white tracer, that seems to run from the ignition to the cpu, or something like that.



Thanks for the help i'm slowing learning how it all works

Keep us posted.A EFI SA would be nice to drive.Once you know how the EFI works then it makes things go by way easier.

ive seen one a long time ago. red 80 rx7, with an an 86-88 motor and all the injection. there is also a 70's spitfire with an na 86-88 13b and all the efi/wiring around here, its cool he usedd the mazda steering wheel and gauges



mike

In case anyone's still reading this post I think i finally am getting close to it starting, I tested a running 86 to see which wires were hot with the ignition on, and found that there are two wires that run from the main relay to the engine harness; exect for me not having a ATP sensor, i think everything else is there it should start. I'll be trying to start it shortly I'll keep everyone posted

sweet :bigthumg:

:bigok: Glad to hear that.Let us know how it goes.

yah keep us posted. whats an atp?



mike

ATP = Atmosheric Pressure Sensor, it detects atmosheric pressure and sends a signal to the cpu. It's located by the cpu and blower motor



I tried to start it, it didn't; but the plugs ended up covered in atf again, i guess i'll take them out and turn it over until hopefully it's good enough to not foul the plugs.



Also I'm not getting power back to the computer from the intake air temperature sensor

ah ok, i know that sensor, it needs that to compensate for altitude, it may affect the mixture slightly. i think it should run with out the air temp also, although that will also affect the mixture



mike

I just didn't connect the intake air temp it's hiding... I'm not real familar with 2nd gens, slowly learning though. I'll keep you updated, i see no reason it won't start (with the exception of atf fouled plugs) https://www.nopistons.com/forums/pub...#>/biggrin.png

clean em up already, you've got us all anxious... now you're going to have to post a video of it starting. https://www.nopistons.com/forums/pub...#>/biggrin.png

Well ge that ATF out and start it already.We're waiting. :smirk: :bigok:

Yeah bro!! how's it going now.

Get it running yet? https://www.nopistons.com/forums/pub...IR#>/dunno.gif

i've tried turning it over with the plugs out, I mean hitting the starter for like 15 seconds about 5 times and I thought i got all the atf out so i put the plugs back in and it kinda sounded like it want to start for a second then I notice it sounds like it's not turning over fast enough and my tach still doesn't work. So i pulled the plugs and once again atf soaked; anybody know what to do now???

sounds like its flooding. if you hook a tach up to the extra wire on the coils to you get a reading? i can spin my cas by hand and get an rpm reading



mike

that wire is hooked up to the plugs that were connected to the old distributor, i figured this lead back to the cars tach right? I pulled the fuse for the pump and turned it over though, then put it back in and the cleaned plugs and tried to start it. maybe a bump start that would just suck to have to get it back into the garage if it didn't work

Can't you just run a wire from the leading coil to your tack like the FB's stock?

so wait if your using the stock dizzy, what is telling the ecu the rpm?



mike

No it has the 86 cas but, I found out that i had connected the wire from the coil to the wrong wire on the 79 chassis, on the 86 it's yellow with a blue tracer so thats what i connected to on the 79 harness, but it turns out it supposed to be yellow with a green tracer so it works now, i have to go to work but check back after 8:00 central time. I will be starting it then, assuming it's not still flooded dispite my efforts :squint:

yah assume its flooded



mike

Keep us posted in this thread.It's a fun project.Just keep thinking that. https://www.nopistons.com/forums/pub...#>/biggrin.png

It's still flooded way too bad to start, with gas and atf, what's the most effective way of getting all of that out to start it??? I've tried pulling the fuse to the fuel pump and turning it over with the starting to get all of the atf and gas out, but everytime I put the plugs back in they just end up getting fouled again. Please help me this is all that stands in the way of it starting, because it's definetly getting fuel, air, and spark. The tach now even works!



Please help I would like to take her out this weekend and tell you all about all the kills!



Help!!!!

If you guys can be nice and not criticize my work, because I'm only 19 and on a budget I couldn't afford to make it look as nice as I had dreamed, but here a some pictures of the project, I really should have taken pictures of the build up. Maybe next time... Anyway, be nice and sorry for the quality the flash travels every bit of a foot, so the dark pictures look horrible, but enjoy.

:bigthumg:

another

I plan on washing it throughly once it's running

https://www.nopistons.com/forums/pub...IR#>/angry.png if only it would start

Here's my custom air filter setup, total cost $50

Should get some pretty good air flow :smirk: