Hello people

My Integra is in bad shape, I installed on him a B20B engine, when it started after the installation it did'nt idle properly but it ran good. I can make it go 120 mph with a smirk on my face, the problem comes when I let go the gas pedal, when the revs start descending it shuts down, and dont want to start again. I get out and open the hood and take off the 5 fuses under the hood fuse box and try to start the engine without the fuel pump working, then I put them back on and with the gas pedal all the way down it eventually will come to life and start up.I've cleaned the IAC valve, my thermostat is removed, water flow is ok.... another thing is, when it shuts down and come to a stop theres a huge gas smell al around the car, havent gound no gas leaks, neither vac leaks, thats what I got for now.