well i posted this original thread
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/buckling-hesitation-backfiring-new-rebuild-help-396440/
I put put new plug wires and found a blown ac fuse and replaced it. This fixed the stumbling that i had in the previous thread but still hasn't fixed everything.
My car runs very rich. It gets lots of whitish/gray smoke at startup (fuel smell) it's not blown orings either. It has good compression also. IT runs very rich and backfires alot. it can't even come close to holding an idle. if you let off the gas it just drops all the way down doesn't even try to idle. I opened the idle control screw all the way but that didn't even make it idle higher or even a little better. The car smells and there is black stuff all over my exhaust tip. It also has trouble starting after it stalls once if it is warmed up.
i have gone through this checklist and im still a crappy running engine
1. new o2 sensor
2. new spark plug wires
3. grounded fuel pump better
4. have fixed all bad conmnections on anything on the UIM
5. do have goo9d compression
6. do have good fuel pressure ( i assume because it has a brand new FPD and if it runs rich it probably has enough pressure)
7. recently cleaned and flow tested injectors (~400 miles) they're not sticking open or cracked
8. new injector o-rings and diffusers
9. new Intake manifold gaskets (upper and lower)

 

I know its not the same kind of car but... I used to have a 94 firebird, in which I installed a supercharger. One day I was driving along and it just started to run extremely bad. I checked all of the ic connections, even had my mechanic Dad look at it. It ended up being a blown ic pipe. It was of course the hardest one to see and get to. After reconnecting it I checked to oil. After running rich for so long, the fuel actually bipassed by pistons and got in to my oil. So I had to do an oil change. My point is look everywhere, looks are deceiving. I know how frustrating it can be. Also check your oil, smell it. If it has a gasoline smell to it then be sure to change your oil or you will have more trouble. matt

 

I just briefly look at the first thread and am assuming you are running the stock ECU. If so a street port using stock ECU does not make the same vacuum at all speeds/loads, except maybe wide open throttle. Being it doesn't your system/ECU will not be able to adjust the fuel mixture correctly. Your engine doesn't make enough vacuum, thus the input sensor called the map sensor will be telling the ECU to run rich. Does this fit your situation??

 

yeah im streetported on the stock ecu and i guess that is a likely possibility but im hoping it's not it. is there any other possible causes that i havn't checked? hmmm. maybe i can find a buddy with a pfc i can borrow and see if that fixes the problem if i tune it for my car.
any other ideas anybody?

 

With a street port you will have far less vacuum at idle. Since there is such a small amount of air passing through then just being a little rich can make the engine run poorly. With likely under 12 inches of vacuum at 1000 rpm its real real rich. I assume you have your smog pump connected and working, if not that will just add the the richness. A PFC is expensive and if I had to do it again I would not have chose a street port myself.

 

That "black stuff" on ur exhaust tip is carbon, your running rich.If your O2 sensor is working it should throw a code, go use a scanner and find your problem before wasting any more money on parts u don't need to replace.

 

Is it any method to reduce it ??

I m actually running rich too, and i would like to know a method to make not too rich

I have below:
Race Port & T78
PFC

 

I have a street port, and with this my vacuum is likely low in a liner faction. Consequently the map sensor is reacting to the low vacuum and over-fueling. I also don't know what Pfc your running but you need to address the problem likely by having the PFC tuned to your needs

 

check the pressure sensor...scanner will help you b4 replacing the sensor..