Ignition problem.

[zanthus]

So I've been driving my 78 z for a few days now because the weather isn't horrible. But 2 days ago I was driving it to work which is about 10 miles away and about the 8 mile mark all of a sudden the car shuts off.

Now I've got no start. I come back later to see if anything can be done and it starts right up. After work I drive it home get about 8 miles and it dies again, no start. After some time (about 2-3 hours) it starts up again. Both times the car just literally dies, no sputtering or anything its almost as if you turn the key off.

The last time I had my multi-meter on me and a sparkplug socket. I took a plug out to see if there was any spark an nothing. I was also not getting any voltage to the coil.

Does anyone have any ideas? My thinking is that its something in the ignition circuit is getting hot and shutting off. Then after cooling down it runs like a champ. Thats the only thing I got for ideas, has this happened to anyone else?

[Z train]

http://www.classiczcars.com/forums/showthread.php?t=36903&highlight=ecm

[mayitin]

Is your igniton module,. Witch one do you have the one on the side of the dizzy or the one inside the the car? when it gets hot it dies once it cools it starts. If can not get one let me know I have both type of modules.

[sblake01]

If it's stock the 78 should have the large transistor ignition module behind the passenger side kick panel.

Edited February 15, 2011 by sblake01

[mayitin]

if it is stock but some people do not know if theyt have a stock one, that is why I ask. then again it can be the ECU, but the wht he describes what it does I prety sure is the module.

[78zcar_blue]

If you believe it is the module, I would remove it and go with the GM HEI module, I have been running it for months with no problems. I found a write up on the module on this web site and it cost about $25 bucks just my 2 cents.

[zanthus]

Anyone got a picture of what the module looks like?

[Zed Head]

Page EE-30 in the FSM has a pretty good drawing.

It has been suggested in other threads that you try cooling the module down when the problem occurs. If cooling it allows you to restart faster than waiting, that's a pretty good indicator that the module is bad.

[FastWoman]

The '78 IM is behind the passenger kick panel. It's a black box that's a few inches by a few inches by about an inch. You can't miss it.

Here's the HEI retrofit:

http://zhome.com/ZCMnL/tech/gmhei.html

I put one of these modules in my car and have been running it maybe a year. Works great. I put a heat sink on the back of the thing.

[mayitin]

If you do not want to go with a nissan part Z blue is right he put the GM module with no problem and is runing great and is only 25. vs 100 and something for a new module you can go with a used one but but down the road it may act up. Zed head is right try to cool it down by puting a cool towel around it and holding it for a few mins.

[FastWoman]

My HEI retrofit was only about $14.25 -- $14 for the HEI module, and 25 cents for the nice heat sink I bought (lots of 'em) back in the 80's.

[zanthus]

Then how do I deal with my factory ignition control module because those directions are for converting a 240 over to HEI module? Would I go about it the same way?