Lucky777

iTrader: (1)

Hi! I hate to be the guy asking the obvious questions, but I pored over old posts, tech writeups, and the factory wiring diagrams and some of what I'm about to ask still goes over my head. I am sorry in advance.

I have a 79 Rx7. I had a low mile 84 GS which I removed the motor from to put in the 79. I'm freshening up the motor a bit, mild streetport, carb rebuild, minimalist wiring and air pump delete, etc. I have never seen the 79 run, bought it with no motor or trans or dash. PO says wiring harness IS all there. This is where I need help.

What is there is shown in these pics.





















Could someone tell me off the top of their head if this IS a complete engine harness, and where I might find a more practical annotation of WHAT all of those terminals hook to(not exactly color coded to the 84 components, connectors may be different, etc.)










ALSO, I have this mess. PO says the PO before him "converted it to run on the newer distributor." I don't know what is what with this mess of looped terminals, and I cannot find an easy to follow writeup on how to convert to run the FB coils and distributor.















This is the distributor on the motor going in















And then, if someone doesn't mind slapping me upside the head with some logic, what are these boxes?












One last question. I realize a can of worms doth openeth with the FB distributor already, BUT, is there a straightforward way to convert the wiring to run the 84 internally regulated alternator?




There are many things on the engine side of the wiring diagram I don't understand. The body makes sense to me now since KCREPU pointed me to a wiring diagram(thanks dude!), but the logic behind certain engine circuits, I'm not seeing. I don't understand the various solenoids on top of the motor, the emissions controls, hot start circuit, subzero circuit, although I'm getting a foggy picture now after a bit of reading. I hope to have a build with minimal vacuum line clusters and minimal nests of wiring, while still having functional gauges(no emissions tests here though).


If there are any "common knowledge" pitfalls you can point out to me, that's great. If there are sensors which are different year to year, something big I may be missing, a large portion of harness I can eliminate with the deletion of A/C and emissions valves, PLEASE tell me now, so I don't have to trip over it for the next few months of this build. I appreciate the help on this as I move forward with the project, and I apologize for being rather dense.



Oh, and if I'm not using the A/C, can I pull that wiring harness off the evaporator box? Thanks!

Lucky777

iTrader: (1)

For anyone who landed here looking for the same info, here's a decent link on the ignition. I think I can figure it out from here, and I'm going to use the ignition harness from my parts car to make it plug and play for the newer electronic distributor.

http://www.mazspeed.com/ignitionswap.htm



I think I'll probably buy a 79 alternator in the interest of not hacking another harness apart.


Now, how do I deal with the various solenoids on the top of the motor, should I change that all over to the solenoids from a 79?

erick31876

iTrader: (8)

The wires are the coil wires, yellow with green tracer-trailing +, black with white tracer-trailing neg.
Yellow with blue tracer-leading+, black with white tracer-leading neg.




That is just how they would be bolted up in the fender, hope this helps

Lucky777

iTrader: (1)

Thanks.

So far what I've found on converting to the new ignition is,

Black and white wire that was feeding the resistors splices into 2 wires, which connect to the positive side of both coils. The igniters hook up positive to positive and negative to negative on their respective coils. That seems simple enough. What does the black single wire that comes out under the dist cap do though? And how do I find the MSD coils everyone is talking about?


I'm still lost on the engine wiring. I'm not finding it in the wiring diagram.

erick31876

iTrader: (8)

I'm not sure what msd coils your talking about, but it's probably the msd blaster 2 coils, you can get them at pretty much any auto supply store, they are basically a universal coil.I got mine from eBay.they aren't that expensive either

Lucky777

iTrader: (1)

OK. Wasn't sure if there were multiple variants of the Blaster II or not. I bought electronic ignition for my Buick a while back and they called that a Blaster something... Anyway.

I think I understand the concept of using the newer ignition with the 79 harness. Power the coils, connect the igniters to the coils, but... Do the coils or igniters ground somewhere? I don't see that anywhere.

t_g_farrell

iTrader: (1)

It will be hard to use the OEM wiring diagrams with that hacked up wiring. An experienced 1st
genner could probably figure it out but if this is your first rodeo its going to be a rough ride.

I would not even try to keep the rats nest on the donor motor and I would seriously consider
a DFIS ignition since you already are &%^%^ wiring anyway.

Lucky777

iTrader: (1)

Got it. Removed question.