'75 280Z: Engine Cuts Out & Has Wandering Idle

[eightbit]

I don't really know where to start looking here...the victim is a 1975 280Z.

I started the car this evening, cranked right over and sounded strong, then died within 30 seconds. I started it again and it would crank over, then die, or hold for a few seconds, do a funny idle wandering thing then settle and then choke. Managed to drive it around the neighborhood, but it would still choke and die. Don't really know if it's something electrical or fuel related.

If it's relevant, I just recently purchased the car, with a known issue with the ignition...when I turn the key to the off position, the car won't die and needs a diode wired into the line off the alternator. Just thought maybe the battery was dead, but electrical system seems to be working fine, and the car cranks right over. Also, the previous owner was kinda nonspecific when he mentioned that the emission controls had been removed... so there's stuff physically cut from the engine harness? Also it has a straight pipe with no cat, if that matters.

Not experienced with Z cars, I'm not sure if any of this sounds familiar. Since I bought it, the car has run strong...this is a recent dilemma, so I can't imagine what was cut was too terribly important, but than again, I don't know.

Any ideas would be appreciated.

[jmortensen]

Not an FI guy at all, but hunting idle is often caused by a dirty throttle body. If you pull the boot to the throttle body you can open it up manually and use a paper towel or rag and some carb cleaner to clean up the blade and the housing.

The idea here is that the blade doesn't seal to the housing, and the small amount of air that leaks around is what the engine runs on. When the thing gets full of soot, that seals it better and then the engine starves for air, which makes it start to surge while struggling to stay running.

After that, someone else is going to have to help, but dirty throttle body is very common, so try that first.

[eightbit]

Thank you. I'll clean it tonight and hopefully that does it.

[eightbit]

That fixed it! Thanks, man.

I'm new to car maintenance. I'll be sure to clean that regularly.