airassault

Ok so I have a 99 GMC Yukon Denali with a 5.7 vortex. Engine was spitting and sputtering and ran bad. Checked fuel pressure was at 52 running. Turned engine off held 45 all day long. Plus fuel pump was moaning. So replaced fuel pump and filter and boom truck runs great. EXCEPT now and this weird when I just barely touch brake pedal (just enough to engage brake light switch) the engine moans. It does it with out the brake pedal being touched by revving engine but it's spontaneous. If you touch brake pedal it does it all the time. It doesn't get louder with RPM. Now it makes the noise careless of what gear it's in or moving or standing still. I was able to get a good idea where it's coming from and u can feel it when you touch the main injector harness right behind the Throttle body. Also when you turn the engine off it makes the same noise but a little louder and a hissing sound for about 3 seconds. What could this possibly be? It wasn't doing it before fuel pump.
Also have replaced distributor coil plugs wires clean MAF IAT and new TPS and air filter