Well gentlemen, I've finally put back together the 81 Rx7.
Got the engine in and trying to see if it will run ok.
I've hooked up as much wiring as I can see connections for.
There are a lot of connectors coming from the harness that goes to the smog solenoids on top, don't know where they connect to.

I suppose this is probably why I have this problem that when I go to crank the engine, it cranks over but won't stop when I turn the key off. Just keeps going.
It seems to me this is a missing ground issue, but not sure, anyone have an idea?

Thanks, Jack

 

The key switch connects directly to the starter solenoid, so check the obvious first: is the key switch or starter solenoid sticky?

 

starter solenoid is sticky. i bypassed the keyswitch and connected to it directly, and same problem. I will take the starter out and the solenoid off, and hopefully I can clean and lube it to fix it? don't really want to buy another starter unless I know the engine is good.

I found two more connections on the wiring, so now left with just two I don't know where they go. Maybe I post picture of them, someone can help?

 

So I took the starter off, removed the solenoid and it moves freely. Took it apart cleaned the contacts, lubricated the plunger, put it back together and bench tested it, and it seems to work normally. Put it back into the car, and same problem.

So it looks to me the issue might be the starter gears are getting jammed a little too tight against the flywheel?? Maybe the spring pressure in the solenoid is too weak??

I went ahead and tried to start it anyway, but no luck. Fuel pump makes noise, there is fuel in the carb. Spark plug wires flash the timing light, so that looks good.
I removed the upper plugs and did a compression test, 90psi front, 85psi rear.
seems low, but good enough to fire?

I'm about to give up, and put the car up for sale. If you are around Sacramento, got a 81 Rx7 for cheap!

Jack