I have a 98 sr20det with many mods including q45 MAF, 740cc injectors, apexi power fc, 60 trim, 272 cams, walbro 255 and more. I have a lm-1 wideband/rpm kit and it is reading around 11 a/f ratio at idle. I got the car running but it is running very rich. I have pulled the plugs numerous times to try to get it to restart by cleanning them which worked a few times. Now the car does not even start. I put in enthalpy's base maps for when they tune apexi power fc also. It seems like my plugs may be fouled now. I was wondering what my issue of running so rich could be. I tryed leaning it out the fuel injectors even more on the compensation percentage for my injector size. I also tryed leaning out my fuel map. Anyone have any ideas. I am running super rich and I am unsure of my problem fuel pressure reads 43psi when i turn on the ignition but i have not gotten a reading while running. I am about to reset the ecu and start over. any ideas

I got it running again by using the old plugs. Fuel pressure is 43 at idle and It was running at 10.5 air fuel ratio it ran real black then i stopped it and it wouldnt start. plugs were very black. I believe i have too much fuel although i tried to turn down the total injector cycle with no luck. its just running too damn rich and apexi wont compensate.

I disconnected my factory o2 sensor to replace it with my wideband monitor... i believe this may be my problem. do i need the factory 02 sensor for the computers idle adjustment and to run it? thanks

the O2 wont cause a no start condition .it dont start working till it warms up to 600 or after 90sec.

if you go WOT while cranking it the motor will run very lean to try and evacuate gas in the cylinder . good thing to know

you're not alone man. i have the same issues. i'll check my plugs tomorrow. let me know if you figured out.

i run hella rich too, it was started before but won't hold idle and it was blowing black smoke out the back. i'll let you know when i get my sh_t start.

what's your setup???

the directions in apexi say that when you first start your engine you should let it run for 30 minutes for the idle to adjust automatically and it will also somewhat learn some settings. I turned off the o2 feeback but i might need it so i am going to try it tomorrow with new plugs and the stock 02 sensor. i will have to drill another hole for my wideband o2 sensor.thanks

Maybe the apexi unit went bad and is ignoring the input you're giving it. If you're both having the same problem, and you both have the same unit, maybe there's a common problem that they have that we're not aware of. Try resetting the ECU, and disconnecting it, then starting the car. Unfortunately, with those HUUUUGE injectors you'll need to swap in the stockies first and turn the FPR back down to 3bar.

Also - IF you are both having the exact same issues, look for what is in common (by way of modifications to the engine; obviously most of the car is the same lol)

Maybe the apexi unit went bad and is ignoring the input you're giving it. If you're both having the same problem, and you both have the same unit, maybe there's a common problem that they have that we're not aware of. Try resetting the ECU, and disconnecting it, then starting the car. Unfortunately, with those HUUUUGE injectors you'll need to swap in the stockies first and turn the FPR back down to 3bar.

Also - IF you are both having the exact same issues, look for what is in common (by way of modifications to the engine; obviously most of the car is the same lol)

sorry for the mis-info but i have a diff setup then his. i got jwt, bb, and stock maf. no piggybag.