heres the story again. 3 years ago trans went out. finally last summer i got money to fix it. went to load car on trailer and fuel pump was bad so i had to replace pump. i put a AEM 320lph pump in my assembly. car fired right up. i removed engine and trans. replaced the trans with a shift kit and 2560 stall converter. put new oil pan gasket and timing cover gasket on engine while it was out. put back in car and ever sense my mileage has been horrible. on hwy with cruise set the best i have gotten was 19.8mpg average around town has been 13-15 depending how i drive. i also put a ZZP 1.0 pcm in while i was doing the transmission. all other mods were done before trans went out and car use to get 28-30hwy and 22-24 city.
list of new parts i have tried and didnt help any
new mass air
new o2 sensor
new map sensor
tried my original stock computer again
tried an after market adjustable fuel pressure regulator setup
Different injectors
even tried a 255lph walbro pump
is there anything else i need to try. i know at idle in park my Fuel pressure is 55psi when i rev throttle it jumps to 70 psi.
i feel that i need to put a stock fuel pump back in the car. i work in a shop and nobody can figure it out, my long term fuel trims are about 12-17 at times at idle. i can get any data that is needed. i just need help to figure out whats going on.