Car is an 86' N/A 100% stock (with exception of header). Theres no spark coming from the leading coil. Theres spark if no wires are plugged in. Theres spark if one wire is plugged in. Theres no spark if both wires plugged in. Tests were determined with 2 seperate timing lights. I've tried various combinations of wires and plugs. As it stands, everything is new and the coil and ignitor were pulled fresh from a running car today.


What the hell is wrong with this car? Grounds are not an issue, trust me. Theres power (new battery). All fuses and fuseable links have been checked. Everything is 100% A-OK. What am I missing? WTF is wrong?

 

how did you determine there was no spark? they have to be plugged in for them to get spark. the wires are grounded with the spark plugs touching the block, so, if the wires are plugged in or one wire is plugged in then its grounded and it receives spark.

 

Does this engine RUN? At all?

 

Engine doesnt run since theres no spark. The engine did run perfectly prior to this. Compression is 100%.


The wires are plugged in properly as they should be. When hooking a timing light to either wire under cranking, there is no response. Two timing lights were used to determine the first timing light was working. Trailing coils fire fine.

Under testing, I unplugged ONE of the wires from the COIL. It fired as it should and the timing light flashed appropriately as it was hooked to the other wire that still remains connected.

Repeated the steps for the opposite wire.

So in the end, it will fire 1 plug at a time, but not both. A new VERIFIED WORKING coil/ignitor was installed and tested versus the old coil/ignitor and the results were the same.

 

Small problem here. Under cranking, the coils may not see enough voltage (due to the load on the starter) to trigger an inductive type timing light. You need to remove all plugs, then disable fuel, then crank. The decreased load will give you a bit stronger spark.

 

I did a couple quick tests.

I been boosting the car from my Miata (while running) so power shouldn't be a problem.

I will say that I tried pulling the CAS and spinning it freely, to which everything functioned perfect. Im going to check my starter connections and main battery ground tomorrow. It might just be that its too #($&ing cold out. Thank god for tomorrows chinook.

 

Follow-up Post:


I solved the problem. It seems my nearly new (less than 1000kms) Spark Plugs somehow became damaged and when I swapped in a new pair, it worked 100% as it should.

Everything works good now. Im happy with the results.

 

I am having the same problem, trailing is getting spark and neither of the leading are, ground is good and no spark from the coil, but also no voltage at the connectors to the leading coils, anyone have any ideas?
thanks

 

When you check the black/yellow wire in the two socket white connector at the lead coil, what kink of voltage do you get??? Odd, because the same source of pwr for the lead coil is used for the trail coil. It's unlikely you'd have one and not the other.

The other wire on that two socket connector should never be messed with if your not familiar with it.

Never ground the BLACK single socket bullet connector on the lead or trail coil.

If you have a spare cas, install the connector off the cas in the engine, then turn the key to ON and spin the gear on the bottom of the cas. Have the lead sparkplug wires laying on the fender. They should spark when you spin the cas gear with the key to ON.

The the electrical circuit for the lead and trail coils gets its ground from the four mount studs that hold the coil assy on the fender. If all four fasteners are installed, there is no need for any other ground to the coil assy. Unless you painted the studs for the coil assy's .

 

i dont have an extra CAS but i took it out and it spun freely, i haven't touched the ground and its not painted, and still nothing. does anyone have any other ideas? tommorrow i am going to try and back track to the last place i get a voltage reading before the primary coil. thanks