1J running lean on take off and under load

[jzxseven]

i'm running out of ideas on what it could be. i just swapped a 1J into an S14. its running lean on take off and under load. idle is in the 13's. i already tried a diff ecu, map sensor, swapped coil packs and even injectors. uplugged tps and still the same problem. so i'm leaning towards tps wiring, but afc reads throttle signal so i'm baffled?

edit: it also goes lean and stumbles when free revving it with a semi hard blip to the throttle, but if i slowly roll on the throttle it revs up fine.

car has:
stock 1J
fmic
aem wideband
ebay y pipe to 3 inch downpipe with a cutout and the rest is routed back to stock exhaust piping
walbro 255 fuel pump
440cc jdm 2J injectors

 

[josh930]

I would get the injectors flow tested. Do you have an air/fuel controler?

What do you mean afc reads throttle signal?

 

[jzxseven]

i would get the injectors flow tested, but its weird how this also happens with the stock 1J injectors. also the car does have an safc neo, but i turned correction off and i reconnected the map signal wire straight to the ecu.

about the safc reading throttle signal, i was referring to a thought that maybe the tps wiring wasn't right, but ruled it out since the safc is showing throttle signal.

 

[josh930]

Did you ever have the resistors replaced in the ecu? I would definitly do that. Also check for a boost leaks. Search the jz section and see what you can find

 

[jzxseven]

i replaced the caps on both ecu's before they went bad for good measure and tested them. working fine in my cressida.

 

[Guyana00]

What kind of fuel pump?