new 750cc x4 and rtek 1.7 vs 1.8 running lean again!
 

Ok so short and sweet
91 fc t2 jdm swap n370 ecu
I bought the rtek 1.7 a year ago or so and installed a new walbrro 255 along with some "re-flowed" used 720cc secondaries, and stayed on the rich side at 10lbs it would go to 13.5-14s! (Afr) and I dealt with all kinds of wonky stuff with the new aem uego wideband going crazy in every situation, tried adding grounds and cleaning up grounds tried a few different things then a month ago I ordered 4x rc engineering 750cc injectors and installed them about 2 weeks ago, started up and didnt want to idle it was idling at like 10 afr if not lower so it was crazy rich but when I got moving and all the way up to wot and around 10lbs the afr's never went any richer then 11.5 wich was awesome, but the idling problem I needed fixed so I sent my 1.7 in and upgraded to the 1.8 to compensate for the extra fuel during the primary stage, installed and now its running lean again just like when I had shitty injectors well sometimes and then sometimes it will stay in the low 12s until I hit 10lbs and then it will shoot up to 13s close to 14s... I dont get it I did nothing but remove the ecu and switch the chip and plugged it back up and hooked the grounds back up.... now nothing should have changed in the 2nd staging above 3,600rpm but its not the same at all WTF? With the 1.7 it was perfect except idle and now its running lean were as nothing has changed but the chip??? Sorry alittle LONG but help!

stock turbo? just go back to 1.7 and 550cc injectors... beyond stock, you're beyond this ecus limits.

Yeah stock turbo and thats not the issue shouldnt the 1.8 stayed the same as the 1.7 in the secondaries range? That map shouldnt have changed just the map for the primaries

1.8 is designed to run with 4x 720cc. You have some other issue going on. Fuel pump re-wired?

I had this same problem. I went to huge injectors. Come to find out my vacuum line to the FPR came off under the intake and plugged it back in and had so much fuel it flooded my engine in boost. I'm running the 1.8 with a safc with 720s and 1200s

I need to check that but I dont think thats what it is because it went from running very rich after I did the injectors at all times to running lean and I didnt touch anything under the hood,all I did was pull the ecu pull the old chip and install the new one soo?.... and ive noticed it seems like the more gas I have in the tank the leaner or more inconsistent it runs? Guess im gonna have to call rtek, that the only thing rhat changed

For shits and grins see if your tank may have started to not breathe and is causing it to lean out. Just a thought

What do you mean unscrew the cap alittle bit?

log fuel pressure

What the hell are re-flowed 720cc injectors? Makes me believe its your injectors that are the culprit.

I thought the same thats why I bought all brand new lol

backprobe voltage to fuel pump? Maybe fuel pump resistor is not switching 9v to 12 properly.

Try rewiring fuel pump with relay. I had a rtek 1.8 and with walbro and fuel pump rewired, I had to trim fuel out with a safc