The V8 Owners Forum -

Just got a Mallory Hyfire ignition control unit 6853(V1-AL) with a promaster coil. On reading the instructions it says that the small black wire is the ONLY wire that connects to the coil - (Neg.) terminal.
But the hotwire ECU terminal 39 also needs to be connected to the - (Neg.) of the coil.
Any advice please?

I would think that the ECU wire to the coil NEG is the signal wire which would have gone to the coil. If this is the case then I guess it should connect to the Mallory input wire which would be the white wire??

You may need to talk to Mallory about your application.!

Coops and I had no end of trouble trying to get the Hyfire working with the 14CUX ecu. The only way it would work is with something called and eztrigger.

http://mallory-ignition.com/media/instr ... _6200M.pdf

You might well have problems with a capacitor discharge multiple spark system when trying to trigger off the coil - the ECU expects to see only one pulse per ignition event.

Is there a separate tachometer output? That might be more suitable to drive the Lucas injection.

Thanks for that chaps.

Perry - Yes I may need t contact Mallory if I cannot solve the problem.

r2d2HP - The eztrigger looks like another coil? Cannot see how this would help me. Can you explain how you wired yours up please.

Dave efi - There is a separate tacho output from the Hyfire unit but I am still left with the problem of both the Hyfire black core and hotwire ECU pin 39 going to the neg of the coil.

Well I did not bother as its more hassle than its worth but coops did.

Basically you have to keep your existing coil. The king lead goes from the existing coil to the eztrigger and the low volt side goes to the Hyfire.

I ditched the Mallory stuff and moved to Emerald ECU