MSD ignition install replace hitachi transistor ignition

[Toddman]

I have a 1974 260z that has no spark. While I don't know where the problem is, I thought it would be most reliable to swap out the Hitachi Transistor Ignition (E12-05K, single distributor pick-up) for a MSD Street Fire Ignition (PN5520) box. I called MSD and they hung up immediately after I told them what I was trying to do. So, I'm assuming I need to disconnect the Hitachi ignition box and take the ceramic resistor out of the circuit and just wire it as if I replaced points with a solid state distributor pick (diagram attached). Does this sound correct?

[NewZed]

Have you already bought the MSD box?  A GM HEI module will do the job too and be cheaper.  The MSD boxes have been known to be difficult.  Sometimes they work, sometimes they don't. Sometimes they work but the tachometer stops working.

 

You would want the MSD instructions for the "magnetic pickup".  Two wires.  That's what the Hitachi system uses.  Actually, there are a few tests that you should do to make sure that the pickup coil is working inside the distributor.  The pickup coil can go bad.  The air gap can be wrong.  If it's broken the MSD box won't work anyway.

[Toddman]

NewZed,

I appreciate the advice. I'll see if I can return the MSD unit. If not, knowing that I need to use the magnetic pickup install is VERY good to know. Thank you!

[NewZed]

Here are some links to how to wire up an HEI module if you decided to try it.  You can do it all from the engine bay, no need to get inside the old module.  It is just unplugged.  I think that you might have to join to download the full documents, but the thumbnails have the schematic.  Used to be free over there but now there's a charge.  There are old posts on the forum about it too though.  Good luck.

 

https://www.classiczcars.com/files/file/64-1977-280z-replacing-the-tiu-with-a-hei-module/

 

https://www.classiczcars.com/files/file/124-instruction-fitting-a-4-pin-hei-module-to-280z-1977-revdpdf/