*91 CRX with b16 swap (obd0) socketed/chipped PR3 ECU

I'm in the process of getting boosted, but I'm currently NA. I socketed and chipped my own ECU and use an EPROM programmer to burn chips as needed (flash atmel 29c256). I use BRE software (since I'm OBD0) and it works great. I went ahead and installed 450cc injectors (dsm 1g blue tops) but made a custom tune for NA since I'm not boosted yet and drive the car daily. Long story short I'm essentially doing all the small bits before the final install.

The tune I'm currently running is basically a stock PR3 b16 tune but I adjusted my fuel tables for 450cc injectors instead of the stock 240's. Started up, idles great, etc.. But it feels mushy from about 2-4k rpm. Almost like not enough or too much fuel.. hard to explain. I don't have my wideband in yet so I can't accurately tune until I do that and turbo, etc.. but I was under the impression that by simply adjusting the fuel tables from 240cc to 450cc that it would run pretty much exactly the same. It feels pretty good above 4k rpm... like stock, but what's going on between 2-4krpm? Am I incorrect in my assumption about simply adjusting the pulse rate for 450's across the entire fuel table, or am I dealing with another issue (i.e. dirty injectors, etc..?)

Thanks for any input...

 

You should deal with injector dead times (since there are different to your old 240's) and indeed, with the fuel pressure.

 

Do you think you could better explain that? I don't fully understand dead times and how I could control those from BRE (Ben's Rom Editor). I don't believe there's a function/script to calibrate for a certain latency for particular injector sizes, but it seems to me it would be simple math. Is this a matter of simply increasing/scaling the fuel table to allow for a little more (or less) fuel? I have much to learn in this.

 

Ok, I tried something interesting. I wanted to essentially cancel the use of the oxygen sensor to see if the computer was trying to overcompensate so I unplugged my TPS sensor to keep the car in open loop mode. It ran much, much better. So I may just create another tune that ignores the o2 sensor altogether using the same fuel tables. Is this a common practice? From my understanding, the o2 sensor is really not a good instrument for telling the computer how to readjust the fuel anway. It can only measure lean, stoich, or rich. When I get my wideband installed, I can adjust my fuel tables accordingly and just be done with it.