76, up and down bouncing idle..

[adeedue]

Help! "Z" enthusiasts!

Checked most posts and haven't found this discussed yet, so thought I'd throw it out there and see if you've any suggestions about my weird idle issues.

Car starts fine, but after revving it up to 3.5k, the tach starts floating at higher rpm's. When I get off the gas, it wants to die, then goes into a bouncing, revving/dying death throw. When I turn off the ignition and restart it, it idles fine again until I rev it up and then it does it's thing again.

Replaced the distributor/coil, and found a bad tach wire and fixed it. Ran good for a couple of quick jaunts, but then started doing it again.

Any suggestions would be/are welcomed.

Thanks...

[Zed Head]

Those are the exact symptoms my 1976 had when the ignition module went bad. If you don't want to pay the high cost of a new/rebuilt stock module, or can't find a used one, you can use a GM 4-pin HEI module in it's place.

[adeedue]

Thanks for reading an responding... may I ask for alittle more info on the GM HEI 4 pin module? Is it any 4 pin module? Or for a particular model car? In your experience, was it alot of work to convert?

Looking at HEI modules at AutoZone they're cheap!

Thanks again for any help..

[FastWoman]

HEI conversion: Easy. Any 4-pin GM HEI module. Some are more performance-rated than others (e.g. will sustain higher RPMs). Be sure to cobble up some sort of heat sink for the thing.

[Zed Head]

I realized after I posted that there is an issue for 1976 (and maybe 75 and 77) owners if they go the HEI module route. The stock Nissan ignition module has another circuit in it to use the second pickup coil in the distributor if the engine is cold. It advances the timing about 6 degrees, I assume to keep the idle up while cold. So you would lose that feature. It's described in the engine fuel section of the FSM. The GM module does require some extra wiring to install, it's not a drop-in replacement.

1977 Camaros used the 4 pin module. This writeup is pretty good, it's for a 510 but the idea is the same - http://dimequarterly.tierranet.com/articles/tech_hei.html

Here's another - http://www.sonic.net/~kyle/hei.html

The same referred to from this forum - http://www.classiczcars.com/forums/showthread.php?878-GM-HEI-Ignition&highlight=gm%20hei

It's just an option for you if you're on a tight budget or just want something that's readily available. It helps to be comfortable with auto wiring.

[adeedue]

Zed,

Thanks for taking the time to respond and listing the links.. what I thought was going to be a nightmare doesn't appears so now. I'll post my progress and let you know how it goes.. my thought is that it'll go well.

Thanks again,

Art