sen2two

iTrader: (10)

So i finally have my version of this up and running.


On page 4 in this thread here: https://www.rx7club.com/old-school-o...36/?styleid=12

But how can I be sure I am not getting crosstalk between wires? Which wires would need to be wrapped or insulated to prevent this?

t_g_farrell

iTrader: (1)

Nice work on the coil on plug setup. I like the way it fits.

The wires from the dizzy to your ignitors could use some shielding. Basically ground
one end of the shield and then have the shielding encase the wires. Don't connect
the other end to anything. You can use heavy foil, wire screen anything that will act
as an electrical fence.

corners

Gents,

I would first like to take a moment and thank everyone involved for putting a lot of time into developing this setup, it has obviously taken a lot of time & effort.

That being said- I’ll share my story.

I bought this 83 rx7 as a pretty well prepped scda (i think) race car with a completely unknown past (estate sale). Over the years I did a mild restoration and tried to sort out as much as I possibly could to make it safe & reliable on the track. On the first track day, everything seemed to be running fine, until the car got hot. It would develop a stumble that seemed to get worse and worse every lap until the car would not want to rev up anymore and needed to be brought in. It would however idle fine.

Long story short for the sake of the topic of the thread, I did a lot of part swapping (fuel system mostly) over the course of many track days which led me to getting into the ignition system. I then read through the entirety of this thread and was very inspired that this may fix my problem.

I did the DLIDFIS conversion successfully and the car fired right up without a hitch. It seemed to run very strong, and the throttle response seemed to improve, however I cannot drive the car as I’m in the process of changing a broken brake rotor.

That being done, I put a timing light on each of the plug wires to ensure they were functioning properly and noticed something I think is weird. Looking at the trailing wires, the light was steady, strong and seemed stable overall. When I looked at each of the leading plug wires all seemed well.... at first. The light was steady and strong, everything looked solid. However, as it warmed up I noticed the light would "flicker". Could this be cross-talk? It looks as though it is missing a spark randomly. Both leading plugs do this (I’m not sure if it's at the same time as I do not have two timing lights), and there is no pattern to it. The warmer it gets, the more it does this "flicker".

Could this be my problem all along? What could be causing it?

FWIW-
-I gapped the pickups in the distributer to .5mm
-The timing is correct.
-I've tried replacing the "pickup plate" (not sure what it's called) with no effect.
-83 electronic dizzy
-4 pin Accel HEI's
-I have tried disconnecting the trailing with no change in the pulse flickering.

Hopefully I provided enough info to maybe get some help with this as I feel like I've tried everything and I'm stumped with this problem. I will post some pictures of my setup asap.

Thanks in advance,
-Josh

t_g_farrell

iTrader: (1)

1. Is your dizzy nice and tight or does it wobble?
If it wobbles due to age or wear it will throw the signal off even if you think its
adjusted right.

2. What coils are you using? Do they ohm out as good per the specs?
I forget the specs but the FSM will have them. Take an ohm meter to each side of
the coils and make sure they are good.

3. Do you have shielding on the dizzy pickup wires to the HEI done? Correctly?
Shielding is good but can cause issues if done incorrectly. The shield should be
grounded at one end and open at the other.

4. Grounds good?
Make sure your grounds are good from the engine to the neg battery. Good
spark requires a good engine ground.

corners

1. No play at all in the Dizzy.

2. FSM calls for 1.22 - 1.48 ohms.
-Coil 1 (Leading) = Stock Diamond coil. Tested = ~1.4
-Coil 2 (Leading) = Stock Diamond coil. Tested =~1.4
-Coil 3 (Trailing) = MSD Blaster 2. Tested = ~1.1

3. I did not shield the pickup cables, but I did isolate them from everything & disconnected the trailing completely for diagnosis. No change while doing so. I've seen conflicting reports about the necessity of shielding the pickup wires, what do you think?

4. The grounds are solid.

hawk 7

iTrader: (2)

What are the disadvantages or advantages over this set up https://www.rx7club.com/old-school-o.../#post11796227 vs. the setup being discussed in this thread?

t_g_farrell

iTrader: (1)

This is the same as your setup. Except you did a coil on plug mount for the coils.

hawk 7

iTrader: (2)

Not my set up, but thank you for clarifying this for me.

sen2two

iTrader: (10)

I just wanted to add how well this worked for me.

My spark is now SO DAMN STRONG that even after I poured fuel down into the motor from an incorrectly set Weber IDA, it still started and ran with no problem. I literally mean poured. At least 6-8 fluid ounces of fuel in each rotor.

This is also an untuned 51ida Weber on a street port 12a which is horribly mismatched. I am also only running Leading ignition with the trailing blocked off.

Only difference is my set up is coil on plug. I'm sure that helped too.

t_g_farrell

iTrader: (1)

Nice to hear sen2two. Thats why we do write ups like this, to help others out.

Look me up at DGRR if you will be there.

rotaryjunkee

Sounds interesting.

Sent from my gs4 using RX7Club app

t_g_farrell

iTrader: (1)

Just a heads up, I'll post pics later this week. I went ahead and added the trailing ignition as well
now. I think the idle is a bit smoother but thats about all I noticed so far. I had a 2G coil laying
about so I replaced one of my TFI coils with it to do the leading ignition (because it has 2
terminals on it) and then added the wires to get the trailing signal to the other TFI. Redid the
leading plug wires and fabbed up the trailing coil and plug wires and used the leading connections
on the dizzy to do the trailing.

I think it took me all of an hour or two to redo this. The coils still mount in the stock location,
even the 2G coil. Liek I said, pics later.

t_g_farrell

iTrader: (1)

Heres some shots of the new setup. I'll followup next post with a story about getting
the trailing timing right.

t_g_farrell

iTrader: (1)

Someday I want to redo all that wiring to use weather pack connectors and such
but for now it works fine. So excuse my crimped connectors and sloppy wiring.

Anyway, once I did all this I went to check the timing. Leading was fine but trailing
was so far off I couldn't see the marks on the pulley So I did the next thing,
I took it out and drove it to see what was up. Sure enough as soon as it got off
idle and advanced a bit the trailing was detonating big time. More
Disconnect trailing, everything is great. Reconnect trailing, bad when things advanced.

So back to the timing light. I put the light on the secondary coil wire and looky the
trailing timing is pretty much right on the mark. More I then put the
light on the T2 lead and woa the trailing timing is right on the mark. Hmmm, thats
weird. So T1 is way off but T2 is right on. What could this be. BTW, this didn't all
happen in one session but tooks its course over a few weeks. I just disconnected
the trailing HEI module until I figured it out.

So I double checked the dizzy and advance vacuum pots to make sure something
odd was happening there. The only conclusion I could think of was that my dizzy
was stabbed 90 degrees off. I pulled the dizzy and sure enough when I put it in
at the start of this thread it was 90 degrees off. Didn't affect leading because its
a wasted spark anyway. Ran fine for years like that and the timing was right on.

This is because I wasn't using the dizzy cap and rotor. Let that soak in a minute.
The leading just needs a valid signal every 90 degrees it doesn't care which lobe
it gets that off of for the most part as long as I could get the timing right. Guess
I was lucky back then

When you use the rotor and cap they are indexed by the flat spot on the dizzy
shaft for the rotor and the cap can only go on one way (well mostly). The rotor
has been designed to fire the plugs based on this. So once I setup the trailing
it was firing 90 degrees early at idle and advancing even farther on acceleration.

So I restabbed the dizzy and now I have good timing all around. Now if the rain
would just stopped I can take it out and enjoy it.

thirteenbees

great thread, I'm curious if plug gaps increased to take advantage of the bigger spark?

t_g_farrell

iTrader: (1)

I'm using rx8 plugs so no gap adjustment available. Seems to get pretty decent spark out of them.

Crusty-SE

I'm in the process of a tfi conversion on my GSL-SE. My trailing ignitor went bad so i am swapping in the good one. I'm wondering why in these diagrams labels by the dizzy (compared to the labels on the inside on my '85 dizzy) T and L are switched? Is it because you run trailing through the leading plugs on the dizzy? Also, what kind of spark plug wires do i need to get?

t_g_farrell

iTrader: (1)

I dont understand your question. Which diagrams? I'm not up on the SE ignition as
I stated in another thread where someone (you maybe?) asked about doing this
for the SE. It should work fine for the SE but you may have to consult the FSM to
make sure you are looking at the same inputs etc for the dizzy.

I do run trailing through the leading dizzy sockets to take advantage of a shorter
spark path.

Get the best quality build your own spark plug wires you can get or afford. I think
I used some Accel wires 7 or 8 mm core, silicone covered. It was for a V8 and I
have over the years been able to make from scratch two sets of wires so far as I
have been playing with a building this ignition up.

Crusty-SE

Ill try to be more clear, the labels ive put inside the dizzy are the same as mine,with the blue trailing ignitor plug on the right and white ignitor plug on the left. If I was to follow the diagram, I would have to put my trailing ignitor to the left (the labelled T on the outside of the dizzy) and then run leading on the right just like in your diagrams. This is confusing me. Hopefully this explains things better

t_g_farrell

iTrader: (1)

I see your confusion and understand now. Those are just labels and the position shown on the
drawing is actually wrong. Your the first to bring this up since I did this in 2010.

Just make sure you have trailing dizzy pickup connected to trailing ignitor and leading to leading.
Its pretty simple really.

I guess I should do some maintenance on my drawings when I get a chance.

Crusty-SE

Ahaha phew im not crazy I knew I was right Lol. It is very simple, well that takes care of that thanks tgfarrell. Hopefully will be up and running later tonight once my ignitor get here

Crusty-SE

Finished the tfidfis and it went smoothly but my -SE still doesnt want to start. Im a little upset I was hoping this would fix this but I guess ive got more to look into. I can say im getting spark to the leading and trailing plugs now.

Edit: Found out this is most likely a fuel issue and not a spark one.

Crusty-SE

Hey its a year later and my -SE has proven itself reliable with the TFI ignition. Rolled over 200k just last week. Just wanted to say you've got to be ready to get this wrong a few times because these diagrams are not perfect and you must use basic wiring knowledge to get it done right. Took me a lot of tinkering with connections to the dizzy and the coils but this mod is very worthy of some praise. Blew two ignitors in the process as well but hell man I couldn't make a diagram any better so just saying use these as a base guide and be ready to switch things around and try again. My issue was all spark, and a couple very dodgey batterys. Anyways thanks for the guide, my car probably would have never hit 200K without it!

cheers

MyT13B

For what it is worth.....I thought I would share my very simple inexpensive ignition modification for wasted spark leading.

I am using the 1980 distributor with the remote factory triggers. I am only using the two ignitors that came on the car by the way.

For the trailing timing I am using the distributor, but, the spark wires are going through the leading path.

For the leading timing, that single ignitor fires two coils. These coils are generic coils that normally require an external balast resistor. These coils are wired in series +-+- without balast resistors.

I wanted to have more vacuum advance for the trailing for improved low load response. The picture is the modification I made to the rotor to allow much greater advance of the trailing timing.

t_g_farrell

iTrader: (1)

Interesting. Doesn't this just increase the amount of time the spark is present on the trailing?
I guess that would kind of extend the firing when advanced. How do you keep the trailing from
firing too much earlier than the leading or is that not an issue to worry about?

Using the stock ignitors will work fine but your ignition will not be that much better than stock.
The real driver here is the combination of the dual leading coils AND the use of an ignitor that
can handle more power like a HEI module or MSD. That said, its always good to see folks thinking
outside the box.