TLDR: Car occasionally stalls fully clutched in and under no engine load when driving, otherwise runs and idles fine. Don't know where to start looking to troubleshoot the issue.



Hello, first time on this forum, I'm also an EXTREME novice to rotaries and I'm a new driver in general (was an FB a wise decision for a first car? probably not but "**** it we ball" as they say). I apologies in advance if this is something that has already been answered somewhere here, I missed something when poking around on google to find answers, or is just too vague to even be answerable but I will do my best. This will also be terribly long winded in interest of not leaving out any potentially important details so read at your own risk. Sorry again.

A couple of months ago I bought a 1984 Rx7 12a in (seemingly) pretty good condition, and I've had no issues with it beyond some expected 80s jank (crusty window seals and whatnot). Recently I've been having an issue where the car will stall while driving, seemingly at random or only occasionally when the engine is under zero load and isn't getting any throttle. For an example, due to me being very new to driving manual, I've gotten into the somewhat bad habit of entering an intersection in 3rd, clutching in, shifting to second, coasting through the rest of the turn, and then beginning to bring back power, rather than doing the downshift fast enough to have the car in gear throughout the turn.

I've found that the RPMs will drop low enough and seemingly not be caught by the idle during the coasting part of the turn, and will end up stalling on me, while the clutch is still fully pushed in. This does not happen every single time, and I haven't found any particular pattern. The engine has no issues starting back up afterwards and idles perfectly normally at ~900 otherwise. it feels like it happens whenever I was at higher-ish RPMs before clutching in, but again, I don't know of any observable pattern.



Some things to note:

-The iconic emissions control system was removed by the previous owner. (I still have it in a box)

-The engine and clutch were redone both about ~20,000km ago by the previous owner. (I have paperwork for what parts were used if for
whatever reason it would be helpful)

-The previous owner put in a strange (?) setup wherein the OMP has been rerouted to feed from a reservoir of premix that lives where the anti freeze cold start injection gizmo reservoir (???) used to live. I have no idea if this is insane or terrible or not. I want to remove it and go to running full premix in the fuel. Judging by the fill line on the tank, it has been consuming it, but still kind of sketchy. I can provide photographs of this if requested but I don't have any good ones on hand.

-I've been premixing ~4ml of oil for every liter of fuel which (to my limited knowledge) is the amount recommended for if you have a functioning OMP. Again, I really don't trust whatever is going on with that thing. I use Idemitsu rotary premix as per my far more experienced friend's request, who has the same year car as me. He has no idea what is causing the issue off the top of his head and lives on the other side of the continent so I can't really just steal him to help me fix it :(

-Its cold-ish here. Maybe makes a difference, I don't know. I don't even let the car move without letting the engine warm up until the choke pops back in, and it has no issues once its warm.



Now, I fully understand that this isn't ANYWHERE near enough information to fully diagnose or even begin to guess at the issue, but I was just looking to put this out there so that, if it sounds familiar to anyone, they might be able to suggest some avenues to begin troubleshooting and trying to better define the issue so I can find an actual solution. Again, I have no idea what I'm done and am definitely in over my head but there's only one way for me to learn this I suppose.

Thank you for your help :)



only picture I have on hand of the engine bay at the moment

 

The oil tank gadget you distrust so much is likely the Rotary Aviation kit to provide two stroke oil to your factory OMP. It is a good thing as long as your OMP is functioning correctly. Make sure to check it at each fill up and refill with your Idemitsu premix oil.

 

Well its good to know that the OMP reservoir system maybe isn't something I need to be pressingly concerned about, as long as its still feeding correctly

Thanks!