Ok so, Im very new to the rotary platform and my current car is giving me some troubles in the mornings. I have combed through the countless threads and havent really found anything like this before. so here's the skinny...

Every morning I go out to my car and turn it over, It usually takes a few tries and it'll backfire once or twice ( I know youre not supposed to flood it ). once it gets started it'll idle fine. its when you apply power that it acts up... itll rev to around 1500-2000 rpm then die back to idle and repeat the process. now.... sometimes it will just work itself out after I shut it off and let it sit for a minute, the only trade off is a spike in operating temp. ( i know its not good to overheat ) now today plugged in a randomly unhook electrical connection near the smog pump ( not hooked up to belt ) and it instantly ran fine, just with and instant temp climb!

Things I have done-
unpleggued sensor ( ill try to get pics )
messed with a lot of little things ( air screw, coil resistance )

I have a haynes manual but it focuses on idle to much, IDLE IS NOT AN ISSUE 850 RPMS

 

As this is the New Member section, I'll keep in mind how my first few questions were when I got my 1987 GXL 4 years ago.

The first thing I noticed is that the Haynes manual is quite lacking in certain areas like the interior. My 1987 GXL has the factory amps still and the Haynes manual only showed a base model. the result was that I got no sound out of the speakers with a new stereo. After checking the 2nd Generation FAQ, it was an easy fix.

These sorts of omissions are why I would suggest returning that manual if you can, in favor of the correct Factory Service Manual found in the 2nd Generation FAQ here for free:
https://www.rx7club.com/new-member-rx-7-technical-256/frequently-asked-questions-2nd-generation-rx-7-1986-1992-faq-fc-782402/

Included in the FSM is a very useful wiring diagram and 'roadmap' of each harness.

Since you said the connector you messed with was near the air pump, it is most likely in the Emission Harness. Connectors in that area are:
MAP Sensor, Air Flow Meter, Vacuum switch (automatics only), Coolant Temperature sensor (back of water pump housing), ACV Valve, alternator (non-turbo cars only) and the passenger side front AAS actuator (part of Front Harness). May have forgot a few connectors, but you'll see all of them in the FSM's wiring diagram.

It would be really helpful if you could tell what color the wires are and how many there are on the connector. Mazda was very good about making each connector somewhat distinguishable from other ones in the way of shape, number of wires and wire colors.

If it helps any, my 1987 GXL was a bit temperamental on cold starts, but that was because I had no cats courtesy of the previous owner. Resulted in the car running incredibly rich and spitting flames at 7000rpm.

 

Ok I will just throw out the haynes, the FSM is soooo much better. Ill snap a few pictures of the conectors I unplugged and try to identify them on the wiring diagram, my car doesnt have cats either but i think the mixture is just a hair rich. this morning it backfired a few times and started right up with full power through the throttle range, hopefully it kinda worked itself out but thanks for the help and I'll keep posting.

 

Might be wise to hang onto the Haynes manual instead of tossing it in the garbage. While the FSM is better overall, it does have a few glaring omissions as well. One such example is thread sizes for each nut & bolt, along with how to remove the rear seat. In comparison, the FSM for my friend's Del Sol does have this information and makes it much easier to get new hardware when needed. Mazda is apparently not too fond of this as they have a BIG markup on hardware. One recent example is the screws to mount the storage bins to their frame. They're self-tapping phillips screws and the dealers charge about $1.20 for each one.

It's been said that both manuals compliment each other pretty well, though I can't personally vouch for it. Aaron Cake would be the person to ask about their completeness as he has both and is experienced enough in the rotary world to make such a judgment.

As for running rich, the S4's auxiliary intake ports are opened up by exhaust backpressure from the main cat via a tube to the intake. Don't ask me where it ends up as I honestly have no clue. But if it isn't hooked up, the car is getting less air than it think it is and runs pig rich. That's why mine would split flames at 7000rpm.

What I always did before the 20B conversion was let the car warm up for 15 minutes before driving, similar to a Power-On Self Test for a computer. It would instantly go up to ~2000rpm, 'search' between 1500 and 2000rpm for awhile, then finally settle down to 750rpm when it was ready to go and at normal operating temperature. I suspect that this strange behavior was due to a fault in the Accelerated Warmup System but honestly don't know and can't find out since my 13B is long gone.

 

Mine will start out on a sputter below idle then slowly work up to operatin temp, the coldstart thing was ripped out by the last owner so I have no answer for that thing, I also pulled the plugs out and theyre black as night, going to replace them asap and see what it does.