So the other day I was at a stop sign about 3 miles from were I live, stick it in first and go to drive like normal, but then the car shakes like its about to die and I loose pretty much all power. I turn off to the side for a minute thinking maybe a plug came loose or something, I check them all, they are all on there snug. When I say the engine is bogged down, I mean it feels like its using 1/4 the power it normally had. So I inch it back home and park it, it wont even make it up hills. It will start up but it shakes when it goes less than 1k RPMs like its going to die, and it smells Really Rich, and everytime you press the gas the exhaust makes a popping noise, kinda like a small backfire. So I tried a compression test, and I dont really know if what I was hearing was good or not, Took a spark plug wire out from the rear rotor, took the EGI out and tried cranking it, no sputtering or anything, just sounded like it was trying to start, then did the same with the front rotor, they both sound the same.


I've heard from a few different people that It could be a few different things, IE Injectors, Rotor, Apex seals, not really sure what it could be though. Its a 1988 Rx7, 84k Miles on a Reman engine.

I took a video of what it sounds like, I forgot to turn off the music while recording so bear with me. All Help is appreciated!

www.youtube.com/watch?v=WeCvWDMd6UY

 

Its running on 1 rotor, you need to find out why. The first step would be to perform a compression test, and this time follow the procedure outlined here:
http://www.aaroncake.net/rx-7/blown.htm

 

Worth a shot to see witch is the rotor not working..
Remove the sparkplug wires off one rotor, crank it,
now if it doesnt start then you know that rotor is working....
Now plug them back in and do the same to the other rotor....
Now if it does start then you know that rotor is not working....
It could be bad wires, spark plugs, injectors, fuel filter, or a big vacume leak, anthing that has to do with spark, gas and air should be checked

 

Just an Update, A few weeks prior to this happening, I ran completly out of gas, maybe fuel pump?

 

Also did what you said there, and it wont crank when either of them are out, meaning they are both good? when both in it will crank, and drive, but very slowly.

 

may have gone lean and detonated

 

Yeah, Ive heard a ton of different things that it could be. Stuck injector, Fuel pump, Vac leak, Blown motor, Blown Rotor, etc. Cant really be sure though, IT really sucks not knowing how to work on rotarys and not knowing a rotary mechanic!

 

Judging by the sound it is running really rich; backfire being caused by extra fuel being burned off ?
My fc, bad coolant seals, also does the bad idle and it bucks whenever I'm under 1.5k - 2k rpm; when warm.
You might want to pull the egi fuse and crank it to see if you get bubbles in your coolant resivear.
I'm just speculating of course, I hope it is just some bad gas.

 

I had a similar situation. I ran on one rotor. Turned out to be one fo the primary injectors not working.

I did all kinda of things to pin point the faulty area.

Like they mentioned above. Remove the park plugs from the rear rotor only.
See if it cranks on one rotor. THen switch. Remove front rotor plugs and intall the rear ones.
See if it cranks on one rotor.

Once you have pin pointd the faulty rotor.
I dont have an injector tester so i did what i could.
I pull out the primary fuel rail, With the injectors being held on by my fingers pointed into a bowl so i do spray fuel on my engine. I told a buddy to crank it. You can watch which injector is working or not.

My problem ended up being the injector plugs. I ordered new injector clips for cheap. Many cars share the same ones. I replaced the 2 primary injecto clips and no problems since.


PS. My symptoms. My car used to run on one rotor randomly. Like i would make a 20 min trip. and 15 mins into it- it would drop one rotor off for about 3 minuted then i came back... for the rest oif the trip. ANd it would do this 2 out of 10 trips. and eventually got worse

 

running out of gas may have caused you to suck up all the trash in the bottom of the tank, causing one of the injectors to clog up.


do a compression test first though.

 

^^ very true. When i first removed my injectors when trying to pin point the problem. I did have some dirty fuel come out. I still use those injectors though.

 

Do a compression test first of all, so you can be sure the motor is not blown. Then check the wiring to your injectors (I had the wiring to the injectors on the rear rotor crack, ran on one rotor like yours). If that checks out, I'd have a shop clean and flow test the injectors themselves.