Now that I have worked out most of the bodywork and brake issues on my base model '88 RX-7 I am moving onto more engine maintenance. I need to pull the upper intake manifold to replace the vacuum lines under there as well as the fuel pulsation damper. I also need to address a mysterious smoking problem. Given my crazy work schedule I will have to complete these tasks a bit at a time at night. I am guessing that it will take me two to three weeks to finish this work. I have a few rotary rookie questions:
1) Is it OK to let a rotary sit for two to three weeks without any coolant or oil in it? (Note that the car will be in the garage and the open intake ports and coolant passages will be covered as necessary).
2) What can I safely use to clean the intake tract / throttle body. Right on the can of CRC throttle body cleaner it says "Do not use on rotary engines". Is there anything out there that is safe to use?
3) I have white smoke coming from somewhere in the front of the engine. It is only visible after I turn the engine off. Probably beacuse the fan is pulling the smoke away when the engine is running. When I bought the car the plastic coolant filler neck that bolts to the upper coolant pipe had a very small crack in it. I thought that was the source of the issue. I replaced the filler neck with the replacement Mazda aluminum one. No more cracked filler neck...but I still get the smoke. So that was not the source of the problem. It looks like the smoke is coming from somewhere around the alternator. I can not see a visible, active leak anywehere. There is some oil residue on the Oil Metering Pump so perhaps the smoke is that oil burning off. However, I read a similar story where it turned out that the smoke was called by a very small leak around the thermostat housing. I just can't find a leak there though. Any thoughts or diagnosis suggestions?
Thanks in advance for your help.
-Ray
For the cleaning, it's safe to use the CRC if you have the intake off. Clean the snot out of it and make sure it's dry before you re-install. Otherwise Sea-Foam is your friend. 
Sitting with no fluids for 2 weeks is fine.
It won't hurt it to sit 'dry' for a while.
Use the normal carb spray bombs to clean the intake. If you get a lot down in the intake and it's mounted on the engine, you'll be doing the engine and yourself a favor by dumping a couple of ounces of oil into the intake runners and spinning the engine over a few times before firing it up. Of course it will immediately kill mosquitoes for miles around.
About the 'smoke'; it sounds like a coolant leak. If the t-stat housing is not leaking, check the two thermo switches below it for leaks, they stick out of the back of the engine's front cover just below the T stat housing. You should have a 'green' one, that's the engine coolant temp sensor and it uses a copper washer to seal it. IIRC the other one is white and damifino what the other one is for, I think it's used as a fan switch on A/C equipped cars to cycle the condenser fan on. Anyway, make sure it's sealed as well. That one has tapered pipe threads, use Teflon tape.
Sitting is fine
Seafoam is fun and a remarkable fixer on a rotary
Can you smell the "smoke", if so does it smell like plastic, coolant, oil?
Thanks to everyone for the advice. The smell is not burning plastic. I think it is oil...but to be fair I do not have a reference for what burnt coolant smells like.
Burnt oil smells sorta like burnt rubber. Coolant has a sweet odor.
Oil shouldn't leak from that area behind the thermostat. If it leaks oil anywhere in the general area that you mention, it would be at the joint between the front 'iron' and rotor housing, just below and behind the 'distributor' (angle sensor). This would be just ahead of the 'Mazda' cast into the rotor housing.
If your leak is below the alternator then it's a very good chance that it's coolant, very doubtful that it's oil. There's a housing that bolts to the front 'iron' which the water pump then bolts to and I have seen a couple leak where that housing bolts to the front iron. The joint I am talking about is right below the alternator, it's the double opening at the top front of the engine in the pic below. Caution: if you take that housing off, there is a shim washer on one of the studs which has to go back in the same place.
Thanks Jensenman! I will give it another "whiff" test before I start dismantling things. I will proceed with great caution if I take off the housing you mentioned.
-Ray
