That could be the ignition module on the side of the distributor, small black plastic box. Early ZXs have the E12-80 with only one plug, the later ones have E12-92 with 2 plugs. https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1BOFA_enUS494US494&ion=1&espv=2&ie=UTF-8#q=e12-92+280zx.

They have circuit boards inside so I'm sure they can fail at some point.

Edited July 23, 201410 yr by siteunseen

That could be the ignition module on the side of the distributor, small black plastic box. Early ZXs have the E12-80 with only one plug, the later ones have E12-92 with 2 plugs. https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1BOFA_enUS494US494&ion=1&espv=2&ie=UTF-8#q=e12-92+280zx.

They have circuit boards inside so I'm sure they can fail at some point.

Alright well we've checked the distributor and the vacuum advance and it appears to be in perfect working order. I'm thinking it could be a gunked up engine or fuel system. I ran seafoam through the car, oil, and throttle body and it does seem to have changed the problem somewhat. It is a little smoother when when it misfires now, and it isn't quite as consistent also. This could be a coincidence, but running seafoam through the engine has definitely given me the biggest difference so far. I might try running seafoam through it a couple more times, or trying some kind of heavier product. And I'll probably check/replace the chts while I'm at it.

This is for a 280z but a zx is similar http://www.atlanticz.ca/zclub/techtips/electricalconnections/index.html

One of the best things you can do to an L Jetronic car.

Alright, well I have a question. Today, out of curiosity, I disconnected the chts while the car was running at temperature. When I did this, the car immediately wanted to die. Is this supposed to happen? I assume it is.

That's normal. The ECU adds more fuel when it's cold. An unplugged CHTS circuit looks very cold to the ECU.

Alright, well I have a question. Is there, to anyone's knowledge, a possibility that when a car gets above normal operating temperature it can cause a misfire? The reason I ask this is because the car started to do it a little more often without having to turn it off and back on again. And I noticed something else today. I stopped for food and parked while I ate it. It was hot out so I kept the car on. Since there was no air flowing, of course, the car got a little hotter than it normally did. And when I set off again, the car started stumbling much sooner than it normally does (about 1500-1800 rpm). And then after I got going for a few minutes, air cooled the car off to where it usually runs and it stumbled as it usually does. So, ya. Is there any possibility the thermostat is letting the car run too hot? And if so, could this, in any way, cause a stumbling problem?

Ignition modules fail in different manners, but there's almost always heat involved. One trick people use to test them, for the ZX module, is to spray them with some sort of cooling spray or applyi ice to cool them down.

Stumbling could be ignition or fuel related but the EFI system will compensate for heat so simple overheating shouldn't really cause stumbling.

On the other hand though, if your air-fuel mixture is on the edge of lean, maybe the extra heat pushes it over. It might be worth your while to try the potentiometer in the coolant sensor modification. In your case it would in the CHTS circuit. I haven't seen ZX people with the problem but many 280Z people have added a little resistance to add a little more fuel to the intake air and found good results. The Z's may have been tuned to perfection and today's gas pushes them over, but maybe the ZX's have it too. It's a cheap easy test.

I bought a 1982 280zx non turbo last month and since then I've encountered a problem. The car will start stumbling and misfiring around 2500-3000 rpms. But the really weird thing is that the car doesn't do this all the time. I will start the car up, and it accelerates as smooth as silk without missing a beat. However, when the car warms up, I'll turn it off, then back on, and then the car will start misfiring at that rpm range. I've checked the air flow meter, the tps, replaced the distributor cap and rotor, replaced the o2 sensor, and a couple other things all with no luck. The o2 sensor did seem to help it, but not for that long. Please help, it's getting quite frustrating , and I'm slowly driving myself insane trying to find the problem. Any suggestions?

have you checked the plugs/wires? and egr system? mine ran GREAT til one day my hubby parked it to change the brakes, then wouldn't start back. when she finally did start, she fell flat on her face. he checked everything from the afm to the plugs, turned out the plugs were fouled due to the egr being stuck. tapped it with a hammer and she cranked right up and ran perfectly again with no more fouled plugs due to running too rich.

Did you ever found out what was the issue??My 82 280ZX n/a started to do the same....

Thanks