silverchris

I bought a non-running RX7 a couple of weeks ago and towed it home. So far getting it running was pretty easy, but has left me stuck as to the idle.

I have sealed all the visible vacuum leaks. I have sprayed around the carb with starting fluid to find the leaks, and didn't find any. I removed the rats nest and that didn't help. So I pulled the carburetor off... and found that someone had removed the gaskets from my spacer. Since I had the carburetor off I rebuilt it and replaced the intake manifold gasket. I made up some new gaskets for in between the spacer and manifold and spacer and carburetor. The car will not idle still. it starts dying at around 1500 rpms and strugles to about 1250rpms and then dies.

So enough of the backstory, here are my questions:
Is there a way to test the idle and transition circuits in the carb?
or any ideas what to look at next?

bahlorm

If the car has not been running for a while. I would suggest first checking fuel filter to make sure it isn't clogged. Also I have been told from many people to check the anti-afterburn vacuum hose. It can also cause problems with idle and tends to wear out easily due to all the heat. Also not sure if you have tried to adjust the carburetor, not sure if it may make a difference or not in this situation though. But since it will not idle at a low rpm I would have to assume it will be most likely a vacuum leak somewhere, or possibly the cat converter is clogged.
Although many other people on here know much more than me. I am still learning a lot about these cars lol. So if someone else says differently, I would go with whatever they say.

rotornoob

iTrader: (2)

maybe a carb rebuild? if its been sitting for a while some of the gaskets may have shrunk/cracked. anti afterburn hose is a good spot to check as well as idle and mixture settings. if that doesnt help, then maybe you still have a vac leak somewhere, although the rats nest removal should have taken away most of the typical vac leak issues...

85rotarypower

First off, the spacer between the carb and manifold acts as a reusable gasket, so no gaskets are required between the carb and manifold at all.

Second, check your ignition timing. It could be advanced too far and causing an issue. Advancing the timing will also raise idle RPM's.

After that, double and triple check for vacuum leaks. If you want to, just go ahead and replace the hoses. The hose is not expensive.

If that doesn't solve your problem, go ahead and rebuild the carb. Sound like the idle circuit is possibly clogged. There is no way to properly clean any part of the carb's internal function without a rebuild.

silverchris

the carb was just rebuilt. All of the vacuum lines have been capped except the one running to the distributor.my black spacer had the two permanently bonded gaskets removed at some point so I made some making sure I made holes for all of the passages between the carb, spacer, and block. My problem is after all of this it still won't idle. I have yet to do anything to the ignition system except to verify I have spark to the leading plugs

here is a video of it running:
http://www.youtube.com/watch?v=pZk6BoLWZns

silverchris

Well, I feel dumb.... Turns out I still had a vacuum leak from where I blocked off the air control valve.... fixed that up with a gasket+rtv and now I can idle!