l just bought a 1985 mazda rx7 1.1 rotary. It has a four barrel carb on it and tonight after driving it all day (i've had it for two days) l was driving up a fairly steep hill and it started jerking violently as if it wanted to stall. l thought l might be in too high of a gear but shifted down and it did the same thing after a while. So much so that l thought it would stall and quickly pulled over. When l tried going up after it was ok but obiously somethings off. l think l know of a couple things that might cause this behaviour but if you could chose the top three things to look at replacing/fixing, what would they be??

Note - spark plugs and wires were new.
- runs great and idles great when warm. after idling for a few minutes at a red light, revs drop to 500-700 rpm and become less stable.

l also have a 1985 12a RX7 & mine does the same thing. But only if l am in 3rd or 4th gear & come down to lower rev's.
A rotary realy likes the rev's, so if ur on a steep hill take it in second gear, if real steep & low speed, 1st.

It would also be a good idea to take it to u mechanic & get him to check the car is mechanical system for any un-necessary play.

And remember, rotary is r very high maintenance & if u want to keep it on the road:

-Check the oil every TWO days. If u dont, & even let it get down for a little while, it can screw ur engine. Keep it topped up. They do consume oil, & u need to be on top of it.

-Check ur water religiously, again, if it goes down & u overheat, big troubles.

-Change ur oil every 3000km preferably.

-Rev it to the red line once or twice a week, l know it sounds crazy but it helps keep carbon deposits down. Remember to do it when in gear & under load.

Also l recommend u get it tuned. Mine does the same thing with the idle, they do have rough idles but a tune will help it over all, performance, drive ability & economy.

Cheer's