Just bought a 87 gxl that has been sitting for a year and right now when the tach drops below a 1000rpm it almost dies and shakes pretty bad. Im a newbie to rotaries so i would like to know what would be causing this.

 

Hmm... sounds fimilar.

Check you TPS - might need adjustment or replaced.. Get a OEM meter, and see if it's bad.

Check for leaks anywhere in the engine bay.

The rpms dropping below 1k is fine, but dying.. isn't. That's no good. When it shakes, is it when it's about to die going below 1krpm?

 

First rule of troubleshooting a rotary: compression check. Do a search for this topic to get an idea of how to do it; if you dont get any good descriptions post back here and I will explain it.

After you confirm the engine itself is good and dtrong, then we'll move on to troubleshooting./adjusting control systems such as idle etc.

 

ahh thank you, I couldn't think of that, about the compression. I knew I was missing something.

 

about the shaking it does it at about 800 and below.

 

After I checked compression, I would get new plugs, or clean my old ones off with a wire brush. This can be done while the compression check is done; you have to pull plugs to do it anyway.

Next I would check for vacuum leaks; get a couple or 3 cans starter fluid, start car(have friend hold it running) and spray around the intake area...start at the airbox, follow the ube to teh throttle body, then around and under the intake where all those vacuum lines are. IF the engine revs up without your friend pushing the gas, you have found at least one vacuum leak near where you just sprayed. Any vacuum leaks and youll have to take apart the intake to find them. Plan to replace ALL vacuum hose then; it'll cost you about 20 bucks, about 20 feet of line.

IF you find no leaks or repair them all and confirm this with another starter fluid test, then troubleshoot the control system; is timing set? have you adjusted the idle up a bit? have you checked/cleaned teh throttle body internal pasages free of crap? have you tested/adjusted the throttle position sensor?

These are most of the things that will cause your problems. They have all been covered in depth before thousands of times; search this 2nd gen section for those keywords to find lots of information and such. Or feel free to ask me.