Air fuel Ratio??
 

My 93 FD 13b with a t3 63 mm turbo and both 850cc on prim and second on a 255 pump and a stock ecu its showing to about 10.5 air to fuel ratio on idling. Does that mean is running rich? and what would be the normal air to fuel ratio? would it be because its not mapped and i need to upgrade into like a power fc and map it?:scratch: thanks in advance

Well when you change injectors on an un-tuned ECU to larger than stock it's going to run rich. From a quick search it shows most people depending on setup like to tune for 13-14AFR at idle. If you don't feel like shelling out the extra money for a stand-alone, there is a number of inexpensive piggybacks that can probably do an alright job at very low boost levels.

The Map-ECU-3 also has AFR failsafes under boost to pull timing and boost if AFR's go lean or knock is detected, they can be picked up for under $400 used. Megasquirt MS3x full stand-alone is around $900 new. Then you have all the other ways of tuning that are more main stream that any tuner will be able to quickly and safely tune.

Good news is aftermarket ECU tuning is getting better and cheaper with more features and built in safety.

Running aftermarket turbo un-tuned is not suggested, with the bigger injectors, you'll likely run rich, but if the boost is too high you have the possibility of running lean and blowing the engine.

Everything about your setup is asking for trouble.
IMO you should not drive the car in boost till you get a real ECU.

There is no good/safe way to run what you have with the stock ECU

What is your full setup?

Its a street port 13b 850cc on both rails on Warboro 255 pump
T3 63mm single
It used to have a hks boost display control but previous owner removed it and also the power fc and so i bought the stock for now to move it from place to place but smokes a lot of sorta blue smoke tho.

Is it bad to run on the street like this but normal driving not too hard? I haven't droven it like this yet.

Right now it doesn't have the hks boost control display since the previous owner removed it as well as the power fc and so i bought the stock for now to move it from place to place. So is it bad drive it on the streets normal driving and not too hard?