Hi, newb here. I've actually been lurking for months. This place has been great for everything about RX-7s.

Anyway, now I have a problem that I wasn't able to find specifically using the search feature.

I've got an 82 GS, almost 85k miles on it. I took it for a long run today and on the way home I took it over some railroad tracks a little too fast. Immediately after that, it jerks a bit back and forth below 4000rpm. If I step on it, over 4000 it takes off smoothly. At traffic lights, it would stall out, unless I revved it above 3000. I tried starting from a dead stop on a steep uphill, and I have to almost floor it in 1st gear to get it over.

The engine sounds normal, no scratching sounds. No funny smells, not yet anyway. When it's parked, it revs pretty smoothly, but I found out if I rev it high (like to 6000), let it drop, then rev it again, it struggles a little bit before 4000.
I haven't checked compression yet.

Is it rebuild time?

Edit:
Now that I've stepped back and thought about it a little more, could it be a carb problem? Something got lodged in when I went over those tracks?

 

Sounds like the bump dislodged some crap that was either in the carb or fuel lines and it clogged your jets. I'd pull the carb apart a bit and try to clean it out with some carb cleaner. You may have to do some disassembly. Btw.. doesn't sound like a blown rotor, if it was no matter what if you floored it, you'd maybe get to 30-40 mph and the car would sound like a broken lawnmower. Good luck.

 

When in trouble ,when in doubt, always check the fuel line filter first. Been there .... done that.

 

Before you start digging into this too deeply, check the simple stuff first. I would start with your ignition connections. Make sure that you did not dislodge your coil/plug wires. Sounds like you might have lost your leading ignition.

 

Thank you, that's what I want to hear. I guess I freaked out a bit. This is my first rotary and I've only had it a few months.

I'm getting sparks from the leading plugs, and I've changed the fuel filter last month, but i'll take another look and try some carb cleaner.