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-   -   No Spark Good Compression & Fuel Pressure (https://www.rx7club.com/3rd-gen-general-discussion-322/no-spark-good-compression-fuel-pressure-1160293/)

machinis 01-14-23 06:53 PM

No Spark Good Compression & Fuel Pressure
 
Fellows, I am writing this post because I've reached Desperation Mode. I've tried the search function with no luck. This RX has sustained serious sun, heat, cold and salt beating since 2013 when I was shipped overseas and couldn't ship it with me.
Car ran fine around 2018 after replacing the rotted fuel lines inside the tank between the pump and sender unit, but after a couple of years would not start. Car will crank, but no spark. Tried plugging in the OEM ECM with same results. I've checked coils and they're within manufacturer's resistance checks (according to 1995 workshop manual). Plugs and wires are good. Fuel pressure good and being sent to the rotors/housings. Compression is good.

Mods: Power FC with Commander (the Commander lights up green, but the screen is no longer showing any data).
Noise: audible buzzing noise inside the rat's nest after cranking and no start.
Visual: the RPM needle is all over the place at any time the battery is connected. Similar indications in the past, where it would return to normal readings after the engine starts/run. I'm not sure if this is related to my problem.

tomsn16 01-15-23 01:31 PM

We encountered a no spark situation that was caused by a FAULTY GROUND of the igniter to the chassis.
Clean the bolts and threads that mount igniter to chassis.


FDAUTO 01-16-23 12:04 AM

How did you verify there was no spark?

The buzzing sound with the no start is likely the iacv. Next time it happens, unplug it while the buzzing is happening to verify.

machinis 01-21-23 06:57 PM

After further troubleshooting, I determined that I have no spark on Leading Coil. Trailing Coils are both sparking. Cleaned off grounds and added extra ones for testing purposes. Tested both crankshaft sensors and both are within specs and reacting to a magnet. Tested for voltage while cranking the engine at both the lead and trail connectors. Trailing is sending voltage, while leading voltage is not. Everything is pointing to either wiring in between leading coil and ignition control module, or the ignition control module itself.


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