So The other day i installed an MSD 6a box on my FD. Car felt great drove it around all day and night with no problems. the next day i started the car noticed a low idle around 500-600 and occasionally jumping to 700

So i checked over a every connection to make sure nothing was loose. let the car warm up and still a low idle. so i got worried thinking maybe the worst had occurred and checked vac and it was was pulling about 16-17inches of vac at about 900rpm when i sat in the car and gave it a little bit of gas. Went for a little drive and the car felt super slow and felt like it was breaking up at WOT. ON top of that my AFR dipped doped down to 10's somewhere.

Today i decided to uninstall the MSD box and return it back to it's stock set up and still had a super low idle. about 2mins after pulling it out and letting it idle maybe less the trailing Coil started to smolder, spark and melt. I shut the car off and took everything back apart and my Coil Harness was melted onto the trailing.

Reassembled everything with a spare coil pack i have laying around and of course the car is doing the same thing.

SO from what i can tell it seems that im not getting much trailing spark or any for that matter could my harness be the culprit i did have to cut into the harness and add the MSD box in that way. but re turning it to stock should fixed that problem ?

can anyone chime in on this ?

Mods are currently Stock ignition with 10mm Magnacore wires and NGk 9's all around

Also im Fairly positive my MSD box has crapped out on me as well.

 

word.

also i mean LEADING COIL not the trailing

 

Sounds like things are wire incorrectly and you have the coil 12V grounding out somewhere.

 

I wired everything back the way it was.

when installed the MSD box i even put a 12v fuse in the line between the battery and the MSD. When i noticed it wasn't working i returned everything to stock.

Yellow and blue to Yellow and blue Black and Red to Black and red it is a pretty straight forward installing and returning back to stock.

I DID NOTICE that before i took everything apart. the coil harness ground was disconnected and i ended up grounding it.......

This is the diagram that i used when i installed everything.

 

I've heard of people frying the stock FD3S L coil with an MSD box, generally why most people goto T2 L coil. However that harness's don't fry. Sounds like, as mentioned 12V switched source grounded. Thats why that harness should be replaced with new ones, along with the other engine harnesses.

 

Well i replaced the coil harness and now it seems im not getting spark on my leading coils. Also i had no idea about overloading the stock FD coils with an MSD 6a box.

PLEASE DONT TELL ME I HAVE TO REPLACE THE ENGINE HARNESS. haha

 

also any ideas would REALLY help me out.

 

You may have cooked your ignitor.

 

I have a spare ignitor and replaced it and im still not getting spark on the leading coil.

 

Then who knows.... fried your PFC?

 

I really hope not i litterally just got a new one like 2 weeks ago.......

 

Check your fuses, get a meter out and see if you're getting power to the coil.

Also, huck that MSD and get a Twinpower. Plug and play.

Dale

 

is there an msd or other coil thats a plug and play replacement for the leading fd coil? sorry for hijacking the thread im having the same problem but i already have a twinpower my leading just died lol.

 

There is no fuse for just the leading coil.

Check the black w/ red stripe wire for 12v power at the leading coil. If it has voltage then there is no ground signal coming from the igniter. If there is no voltage then something is wired wrong, since your trailing coils are working and it is the same 12v wire that feeds them all.

The igniter gets it's signal from the PFC pin 1H, check the wire for continuity from the PFC to the igniter.

 

not plug and play but a very cheap upgrade option. switch to the t2 (any second gen rx7) leading coil.... you will have to cut the connector off of your coil harness and add 2 terminal ends (open loop) to connect the t2 leading coil... i did it and havent had problems since/yet... i know a bunch of people do this as well

 

So i got off my lazy *** and did some work on the FD.

So here is what i got so far.

There is a signal coming from the Red black wire on the coil harness......

I checked the pin 1h which is the brown and silver wire on the far left of the ignitor harness and this is getting no signal.

 

So today my buddy came by and we did some tests of the power FC to the igniter and the igniter to the coil harness

We pulled up this



and we tested the coil harnes to igniter for continuity and came up positive.

we also tested Power Fc to ignitor leading coil and it was getting voltage as well.

checked the ohms of primary winding and that was fine and we also check the where we put the actual spark plug wire ( secondary winding ) and it was at 0 ohms.

 

my trailing caught fire drifting at the track once. i had shorted some wiring after rubbing through the harness with my front tire.

 

well i figured it out turns out my damn leading coil was the problem.


Check this out my buddy and i where talking about how the connector on the 7mgte coil pack look just like it will connect right too the the FD coil harness. So a friend of our happened to have a set laying around got it back home an it plugs write up !!!!! not gonna use it but at least i can get back to getting the car mobile.

 

1. Take the MSD and throw it in the trash.
2. Get an HKS Twinpower, new Mazda coils, new Mazda ignition harness, new NGK spark plugs and wires.
3. Install everything and your problem should be solved.