Hello all, I was trying to see if anyone had or could point me in the right direction for a diagram. I am looking for a diagram on how to make the voltage spike piece that would go inline with the negitive side of the coil to the ecm on an fuel only tbi system. I read in a page somewhere that under normal driving that these spikes will smoke check an ecm and that a special resistor/capacitor has to be put inline to stop this. Thanks in advance for any info.

 

On a stock system the negative side of the coil doesn't go anywhere near the ECM. The ECM gets the reference pulse from the ignition module. It is a 5V square wave.

I can see where what you are asking about would work, how well, can't say. To do this will need a low pass filter and a voltage clamp (zener).

By not using the ECM to control the ignition timing you are losing a lot of capability. The GM ignition module can be fireed by any number of pickup coils. And can be remote mounted on a heat sink.

RBob.

 

Thanks RBob for the info, you wouldnt happen to have diagram on that would you. I am a newbie but I am a spnge now too, soaking up all the info I can get. I am not running a stock system the ones I'm tinkering with go on jeep engines and are wired to use the ford ignition module stuff. From what I see Howell uses's this voltage spike thingy in there wiring harness. I also read custom-efis's manual on building your own system and he referenced it too. Thanks in advance for any more info.

 

I asked the same thing some time ago, see here:

https://www.thirdgen.org/techbb2/sho...highlight=ford