Hey all, I got no spark on the lead coil in my 85 12a.... I swapped the coils around and still nothing on lead coil....checked with a voltmeter and nothing to the lead cool wires......

Where should I look next.... Unwrapped the wiring loom a bit but no obvious breaks

Thanks

Paul

 

You more then likely need a new leading ignitor on the distributor.

 

Swap the ignitors, see what ya get.

 

so the ignitors are mounted on the distributor, Correct?...if so how would that stop the coil from firing.....doesnt it go Coil ---->distributor -----> engine

when i was playing with it today....i thought it was ground issues...so i made a jumper wire from one negative coil terminal to the other......which then gave a spark out of the coil wire......off either coil.....

still doesnt fire up though......but i think im also having starter issues which isnt helping either.....

sorry if this sounds stupid, but id rather sound stupid than f*&k it all up.....so i welcome all advice.....and explanations....

Thanks

Paul

 

The ignitors are on the distributor correct. Distributor ---->ignitor---->coil---->cap---->rotor---engine. No ignitor no spark . If you jump your trailing coil to you leading coil you will get spark .only it will fire when you trailing does since it is getting the signal to fire from the trailing ignitor. A engine will run like crap with only a trailing ignitor . But will run fairly decent with just a leading.

 

Someone else (above) said to swap the ignitors - and that's a good first step to rule out the ignitor as being the problem. These are held in place with 2xFlat/Cross head screws and while the front is easier to get to, they can be swapped Leading to Trailing in about 30min if you take your time. If the car starts afterward - and runs okay, the one you had in the Leading position (*now in the Trailing position) is bad. Leading ignitor is the one closest to the front of the car. If no change in starting/running - then your ignitors are probably both fine - though I swap them back anyway - and start looking elsewhere.

The J-109 ignitors are known for being somewhat problematic on our cars, as they're mounted directly to the distributor and generate their own and pick up a lot of heat from their location. I install ignitors with some CPU paste to help with heat dissipation from the ignitor to the distributor body, but unsure if this extends their life. Nowadays, I just carry a spare ignitor in the glove box and it's cheap insurance and troubleshooting.

Don't forget to return the wiring on your coils back to original or you'll kill your spark intensity and fuel economy. The engine will run on Leading spark alone, but Trailing spark is there for complete combustion, better torque, and greater fuel economy.

 

OEM ignition is weak sauce. Swapping ignitors is a good first step.

Think about doing a DFIS ignition in the future, helps witha lot of issues.

 

Got it fixed..... Wire was broken under the loo covering right down by the igniter connection

Only noticed when I went to change the igniter