RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   1st Generation Specific (1979-1985) (https://www.rx7club.com/1st-generation-specific-1979-1985-18/)
-   -   Ignition Woes (https://www.rx7club.com/1st-generation-specific-1979-1985-18/ignition-woes-474050/)

Vin 10-19-05 10:23 AM

Ignition Woes
 
*1980 RX7 SA with stock ignition.
*No spark from the leading coil.
*No spark from the trailing coil.
*Both coils get 12.7v.
*High tension wires are good.
*Igniters are working.
*The tach goes to 6K when the key is turned to the run position and drops to 2.5K when the key is turned to the starter position.
*The car uses J-105's.

Since the tach does jump does that mean that my dizzy is working?
Any suggestion?


Thanks,
Vin

smnc 10-19-05 10:35 AM

I'd say it's a Dizzy problem, but I don't know jack about points-style systems...

Vin 10-19-05 10:39 AM

No points
 
There are no points.

Thanks,
Vin

smnc 10-19-05 10:59 AM

My bad...
I still don't know enough about 80's ignitions... Sorry.

I don't know what the difference between the J-105 you use and the J-109's the newer models use...

On GSL-SE's the Tach is triggered by the trailing coil, so if the coil isn't firing, the tach should read 0...

Jeff20B 10-19-05 03:09 PM

The '80's tach is triggered by the leading coil because the trailing was semi-firing in order to feed a healthy rich flow of unburned hydrocarbons into the thermal reactor. This was to keep the fire lit inside the thermal reactor.

That's all I know about the '80 style ignition.

Oh wait, there is one more thing. The reluctor of an '80 dizzy has a backwards curve which leads me to beleive the J-105 ignitor triggers on a positive-going pulse rather than a negative pulse, as is the case with J-109 and GM HEI. The solution, I suppose, would be to reverse the two trigger wires if using an SA ignitor on an FB or vice-versa.

smnc 10-19-05 03:27 PM

Lol... well, more than I know Jeff...

Vin 10-19-05 05:31 PM

Thanks
 
Thanks,
Vin

Vin 10-19-05 08:27 PM

Bump
 
Bump

Vin 10-22-05 04:37 PM

Thanks all!
I just got the ignition system back on line. I ripped everything out and rewired the system without the interrupt circuit. Spark is huge. Now on to carburetion.

DLIDFIF should be easy now that I've gone through this.
It was not easy to figure out that the interrupt circuit was wacky. I must have done something to make it go down :dark:


All times are GMT -5. The time now is 12:23 AM.


© 2024 MH Sub I, LLC dba Internet Brands