Ok so I had a previous problem with my car caused by trailing timing being way too advanced. When we hooked it up to a light the trailing was firing on the leading mark. No amount of adjustment would put it where it needed to be.

A couple days ago the belt decided to come apart and on its way out grabbed onto the dizzy cap, pulling it off and making contact between the cap and rotor, effectively blowing the rotor to pieces and mangling the inside of the cap.

I got a couple used spares laying around but they are not very good so I had an idea. I re-timed the trailing to be zero split again. Now both coils are seeing a signal at the same time. I then ran each coil directly to both leading plugs. The car starts right up and is running beautifully. Dizzy cap is in place just to keep any nasties from getting into the dizzy.

My question is this, is there any reason I should not leave it like this? As I see it I have eliminated 2 parts that can wear and fail.... The timing is all taken care of as normal and the coils still get their signal as normal. Will this route cause any further issues or bigger problems down the road?

this is what it looks like. Yes i am aware the battery tie down is missing.

 

Why not just convert to DLIDFIS? With your current setup, if you kill an ignitor or coil, you are SOL, with DLIDFIS you have the replacement parts right there to drive home.

 

That makes sense but as it is if one coil or igniter takes a dump than its pretty simple to pop the rotor back under the cap and wire the leading wires back up like normal. I already carry extra igniters, coils and wires just in case. This was done to make the car drivable until the next payday when I can just replace the cap and rotor.

Just wondering about possible issues it could cause...

 

There are no issues as long as trailing is zeroed, as you said it was. Congrats! You just did an old school direct fire mod.

But yes, go for DLIDFIS and have peace of mind.

 

You know, in 20+ years of ownership, my SA has failed exactly ONE ignitor... perhaps J105's on the fenderwell are more robust and less exposed to heat and vibration than J109's on the dizzy?

 

Well my SA ignition bit the bullet this winter and it looked like either the ignitors
both failed or the circuit in the SA ignition box was fired. I did see some scorched
looking components in there. I think 30 years is a pretty good run for any ignition.
Now I have easy to source Ford coils, GM HEI ignitors, and no trailing plus a
stronger, better ignition than before.

I think after exhaust and intake, the ignition is the 3rd most important modification
you can make on these cars for performance.

 

I support this 100%, the j109s on the dizzy take a lot more heat/abuse than the early ignitors mounted on the fenderwell. I don't own a running SA, but i have been through a lot of FB ignitors on various cars.

 

+1, in 15+ years (and 15+ cars) ive only killed 1 ignitor.

its not an audi....

 

Not to jack the thread, but I've never lost an ignitor. What are the symptoms if you do loose, say the trailing ignitor? Obviously if the leading is shot the car won't run, but how do you know if the trailing is gone? Just curious.

 

If you lose the trailing ignitor your tach wont work. Car will still run fine. Leading, like you said, it wont run, because from what I have read is connected to the fuel pump. Have never (after 6 rx7s) lost an igniter myself.

 

Not on an SA, you'll never know the trailing has gone out. Also if the leading goes
out on an SA it won't affect the pump. At least not in my experience.

For the leading you will usually notice it when the car gets hot. It will start and run
fine but then as you get going down the road and it gets good and warmed up,
if the leading igniter is going (or the ignition in general), it will breakup and
stumble and keep doing this until it gets worse and worse over time. It doesn't
always go all at once. Its sometimes hard to tell its an ignition issue and you may
chase down false leads like fuel pump and filter issues and carb issues. Ask me
how I know

 

Hmmm, learning something new everyday. Never had an SA....yet

 

one of our techs played a joke on me once, and unplugged the leading ignitor.

car was hard to start, and didn't want to idle, it did run though. i think i even drove it home on the freeway

 

Only clues I've ever found regarding trailing ignition failure on an SA are subtle; The one time I lost my leading ignitor, I got home by swapping the trailing ignitor onto the leading position. Took me a few days to find a new one.

Without trailing on a stock SA, the thermal reactor tends to run hotter, and the car's more likely to backfire a bit on high-revved shifts. Given the complex plumbing of the stock SA exhaust, I'm of the opinion that running long-term without a trailing leads to early failure of the primary downpipe due to overheating, right at the point where the two heat exchanger sections meet.

SA ignition system actually cuts the trailing ignitor under some engine conditions to increase the amount of fuel making it to the thermal reactor, which improves emissions by keeping the TR hotter. Main reason why SA's take tach signal from the leading coil.

 

Exactly what I was looking for. And this is also why we ask everyone to SEARCH through older threads for your problem instead of starting yet another new thread on a topic that has surely been covered before on this website.

Modifying the thread title to help future researchers.

Thanks, gents, I'll see if this cures my situation on both cars.