I checked my trailing wires with a timing gun and nothings comes up. No rpm or flashing light.

Hooking up my leading wire I get it hitting (haltech lock set to 5) on the yellow timing light. It fluctuates a bit but general its right on the yellow mark.

Is the trailing wires supposed to fire to??

 

Yes.

The problem is that even with the stock ECU, most timing guns will not pick it up.

You can try and move the inductive pick-up close to the spark plugs side of the wire - this is what Mazda recommends.

If not, I have found that pulling the spark plug and letting the bare end of the spark plug wire fire to a grounding point can easily trigger most inductive timing lights.  I think the longer "gap" generates an easier signal for the inductive timing light to catch and read.


-Ted

 

Well pulled the plugs out and they did fire once..........

They don't fire anymore. Cause??

I changed out coils same thing. There is 12v on the coils to. No problems there...


Ian

Any ideas to why the trailing would not fire. It did work before??

 

Heh. Try this (briefly, only)... Pull the spark plug wires off the trailing coil at the coil end, one at a time. Have someone crank the car while you watch. There should be a nice spark between the open plug wire and the nearest ground. If not, then your coil pack might be shot. Mine gives a superb spark on each post when I do this. Quick way to see if they are firing.

-- D

 

I'm having the same problem, the trailing side does not fire at all at idle, i checked it with the light and plugged a sparkplug into one of the wires and grounded it, nothing, but if I thump the throttle, the light and the plug will light up like fire works, but only under load, once the engine reaches a desired RPM the trailing side shuts down agian. Is it supposed to do this?

-E

 

real quick....if your tach works, your trailing coils are firing. (unless you hooked it up some other way)

 

Heh... good point. Forgot about that. However, it doesn't help if you want to verify the timing split. For that you'll still need to get the inductive coils to pick up. And I think it only really means the *ignitors* are working, not necessarily the coils themselves. But it definitely does mean that the trailing coil packs are getting ECU signal.

 

tach is tied to leading coils

 

Not on an FC, at least. Yellow wire off the trailing coil pack is your Tach signal.

 

i know nothing of FC's

 

And I know very little of FDs.

 

So if the tach is working and the coil is not producing spark at idle, that means?..ignitors are good coils are bad/weak?

 

Well wait. Producing spark and showing up on a timing light are two entirely different things. When I say pull the line off, I mean leave the coil pack with one line connected (e.g. rotor #2) and one line completely off it (e.g. rotor #1). At idle (which will, of course, be a bit lumpy) there will be a nice spark flying from that open coil post to the nearest ground.

The reason I say do it this way is that if you just ground a spark plug the spark isn't always visible because it needs an air gap. I found that if I hold the spark plug (body and all) a few mm away from a ground then I get a nice spark regardless of rpm. But its tricky, and by just pulling the entire spark plug lead off the coil post it would spark at idle like a ****. Was hella fun playing with it. Do it one at a time so the spark doesnt jump down the throat of the other coil and potentially overload the other side. If it doesn't spark at idle then, you may have a weak coil pack. I had one trailing coil pack that didn't fire one spark plug reliably but fired the other one just fine. I replaced the coil pack and no more problems.

 

Ok, heres what I did this evening, started the engine with the T2 wire unplugged from the coil, holding the shaft (the metal part) of a long screwdriver i stuck the screwdriver into the terminal. Common sense tells me that it should have bit me, but nothing happened. So still holding the screwdriver to the terminal with the engine idleing, i had a friend bump the throttle, i still cant feel the tips of my fingers, but i am 100% sure without a doubt that the coils are not fireing at idle. Is this normal?

 

nope.

 

Be careful with that **** .. EFI systems can generate enough current to kill you...

 

Actually, not really...unless you have a pace maker.
Spark plug power is high voltage, low current.
Stock coil voltages are on the order of 10,000 to 20,000 volts.
But, current is generally under 2 amperes.
It hurts like hell, but it generall cannot kill you.


-Ted