Redwood

Background: I have an 88 13B n/a sitting in an 84 right now. I'm using the stock 88 ECU and wiring for the engine and the 84 wiring for all body functions. The engine ran in my old car but has not run in this car.

Problem: When I put in the wiring from the 88, I cut out wires that I thought I wouldn't be needing like lights and such. Unfortunately, I may have made a mistake and cut a few others (ones I do need). Now, I'm trying to troubleshoot it and having problems. The biggest problem is I am not getting any spark.

To try and solve the problem I have been tracing the wiring back from the leading coil to find a break in the circuit. I have power coming into it via a B/Y wire from the main relay. However, the other wire, which is Y/G, does not have power when in the "on" position or when I'm cranking it over. There is also a third wire, which is B, on the leading coild that is loose.

Questions: -Could someone please shed some light on this through experience, guesswork, or knowledge?
-Specifically, should I be getting power at the G/Y wire when the engine is turning over?
-Does the third B wire on the leading coil need to be attached to anything such as ground or a sensor?
-Would it be a good idea to purchase a complete wiring harness from someone in order to ensure wiring isn't the problem?
-Is there a standalone ignition system I could purchase that would allow me to rewire the whole thing (meaning the ignition system)?

Thanks to anyone who even reads this. I'm at a loss here and need this car done soon. I do appreciate it.

NOPSTN4EVER

Why not go whith a distributor and coils from an older car and loose the digital igniton? I dunno it might work
I converted my 88 to a carb setup and that is what i did.

Redwood

BUMP

I know there's more knowledge to tap into then that.

HAILERS

No, that third wire if its black with a bullet connector should go nowhere.

The yG is the trigger from the ECU. The cas signal goes to the ECU and the ECU sends a trigger signal to the lead coil assy. That y/g can be 0 or 5 volts.

I put a N326 ecu and cas in a 82 car just to do something, and it worked. There is a thread I used to help a fellow out who was putting a rotary engine in some other type car and I remember there was a lot of info on that thread. I'll try to find it in the next hour, depending on WORK load at work.

EDIT; Most important, the lead coil MUST have a good physical ground to the chassis or it WILL NOT fire at all. Period. Talking the attach bolts on the coil assy to the chassis type ground. Will not fire if sitting on a pile of rags. I proved that to myself.

Icemark

The G/Y is a switched negitive signal from the ECU. It will pulse to ground everytime the coil is supposd to fire. There should be voltage resting on it on all other times as the circuit is not completed. This wire can be only tested with a Digital Multi-meter. tetsing with a testlight will blow the output in the ECU

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Quote:

Does the third B wire on the leading coil need to be attached to anything such as ground or a sensor?

There is a single black wire with round connector is that the one you mean??? If so that is a test connector and not normally used.

Quote:

-Would it be a good idea to purchase a complete wiring harness from someone in order to ensure wiring isn't the problem?

Perhaps... depneds on how bad you chopped up the harness

Quote:

-Is there a standalone ignition system I could purchase that would allow me to rewire the whole thing (meaning the ignition system)?

I know the haltech will control the spark and igntion and I am sure someone builds a crank sensed coil assembly, I have seen it advertised in hot rod mags. I would not recommend going back in time and using a distributer though.

HAILERS

This thread: https://www.rx7club.com/forum/showth...threadid=59266 might help. There were a lot of jpgs out of the fsm attached and in one post I listed the only wires that needed to be attached to the ECU to run the car.

HAILERS

You might start by getting a meter and sticking the lead in the back of pins 3I, 3J on the ECU to see if there is power getting there. Key to on when doin that. I'd check for a good ground on pins 2R, 3A, 3G, and 2C. If that all works ring out the circuit to the cas from the ECU. If thats no good the ECU won't trigger a signal to the coil assy. See a jpg on the earlier post for the ring out.

This:https://www.rx7club.com/forum/attach...&postid=501705

https://www.rx7club.com/forum/attach...&postid=501741

https://www.rx7club.com/forum/attach...&postid=488897

https://www.rx7club.com/forum/attach...&postid=488879

https://www.rx7club.com/forum/attach...&postid=488875

https://www.rx7club.com/forum/attach...&postid=488871

Redwood

Thanks to both of you very much, I should be able to route out the problem (hopefully just a bad ground somewhere). I'll freshen up this thread when I get it running. Thanks again.


Are you saying that I blew my ECU by using a testlight? What exactly does that mean?

Icemark

The output is designed for a 5 volt 10 Ma signal.

If you tested the wire with a conventional test light with a light bulb in it, you sent 12 volts at 1.5 amps down that wire. That's double the volts and 150 times the amperage.

I would be very very surprised if you didn't blow the output up if you used a test light.

Redwood

Okay, got the ignition working. Now take a look here for the next problem https://www.rx7club.com/forum/showth...hreadid=101961