I looked into this upgrade, and all the information was aimed at the 240Z, which is great because it uses points. One article was for the upgrade on a 77, but the wiring on a '78 is different enough that I think it deserves its own writeup. The connection of the GM HEI module to the distributor seems fine, but what do you do with the ignition box inside the car?

So, is there a writeup for the GM HEI module upgrade specifically for the 1978 280Z, using the stock 280Z distributor, not the ZX one?

thxZ

Try looking at zdriver.com. I think there is a writeup over there.

On the only 78 I've ever seen with the GM HEI module modification done on the 78 distributor, he left the stock module in place reasoning that if he ever wanted to return it to stock that would make it easier. Are you having trouble with the OEM setup? I never did.

Their search system over there must be wackier than it is here.

Edited February 7, 201213 yr by TomoHawk

Sometimes it's easier to use Google. I got this link by searching on HEI 280Z. You'll need to be logged in to see the pictures in the writeup.

There seems to be a problem with the spark.

The engine runs smoothly, but during a dynomometer test, the guy couldn't get a good enough signal to measure the RPM. The timing light confirms that there is an intermittent miss on #1. I expect consistent, rhythmic light flashes, but every few, a flash is missing. I suspect the ignition box may be faulty or dirty connections, or whatever.

In any case, parts are getting extremely expensive, and rare, so modern alternatives are good to have.

Obligatory question: have you checked plugs/wires/cap/rotor?

Not in the last week or two, but after the dyno test problem, I went through those things and it all looked fine.

You can just unplug the stock ignition module. The wires to the tachometer and the ECU are separate and will not be affected. I did this on my 1976 car and it's been working fine for over a year.

I'm pretty sure that FastWoman has an HEI module on her 1978 car, if you wanted to send her a PM to get another opinion.

I summarized the writeup from ZDriver. It doesn't mention the 280Z ignition box, but we are still discussing that.

Upgrade - Chevy HEI.pdf

Edited February 7, 201213 yr by TomoHawk

Am I missing something?? I don't see anything in that pdf showing the hookup(s) at the distributor......

I thought that the wiring diagram was too simple...

I think the wires labeled 'ECU' are for the distributor, but I will cross-check things.

Edited February 7, 201213 yr by TomoHawk