Ok here's the problem with my car and it's bugging the crap out of me. The car has a built gsr bottom end and it bog's and hesitates at around 2000-3000 rpm only if I give it full trottle to the gas pedal, but if I just barely ease gas into the engine and let the rpm climb slowly, the car runs fine and doesnt bog and hesitate as much. I know the car runs lean and it has something to do with the fuel/air mixture so I installed a apexi VAFC to adjust the fueling to the car. The reason I know is because I installed my friends chipped p28 all motor ecu with high fuel/air mixture and it runs good. After I took out his ecu it's back to normal and still doing the same thing. I dont want to add too much fuel to the vafc cause I dont want to blow my map sensor. I also adjusted the sx adjustable fuel pressure regulator so the pressure gauge reads about 48-50. Does anyone know what the problem may be? There is no CEL and car starts up fine. Just when its cold the car just doesnt want to go. I'd have to rev it up to about 4500 rpm for the car to pick up. After the motor warms up it drives ok but still bog and hesitates. Any one ever run into this problem or has seen and fix this problem...please give me some info.

 

get it tuned if you can run a diff ecu (which i dont know why wont sence boost) and it works then that obviosly is your problem also you are pry to rich thats why its bogging the n/a ecu leans it out

 

So on the apexi vafc I should lean it out? I thought that all n/a ecu's are programmed to add more fuel to your ecu?

 

try leaning it out what does your air to fuel gauge say that will give you a ball park

 

I leaned it out to -30 on all rpm ranges from 1k - about 4k than went back up to positive on the high rpm ranges w/ the vafc, and my air/fuel gauge says it's still rich when at idle? dont know if it's working properly or not, but last time i hooked it up to my other car it did.

 

lean it out down low with the apex and leave it the same up high