I put a 96 accord f22B1 engine into my wifes 92 honda accord EX. AUTO TRANS

Most everytihng on it works fine, except a few minor bugs.

The engine has no check engine codes

1. Whenever the car is turned off, there is a humming noise coming from what seems like the fuel pump. It sounds like bees in the fuel tank, and the fuel pump has been turned on with a scan tool and been told to pump itself. It happens intermittently. not all the time. it goes on for anywhere from 1 minute to an hour then stops. then fuel pump system has proper pressure, and the injector and fuel system are fine. What could it be?

2. Whenever the outside air temperature is cold, the car will not idle properly. It will idle at like 400 RPM's and the car shakes and it feels like the car is falling apart. The car also sounds like it is running loudly. However, once you get it down the road and the temp of the engine heats up for about 10 mins, the engine runs quiet and no idle problems are present except for a searching idle.
The engine has a searching idle ONLY when you go from drive to park. When you are in drive, the roaming/vroooming idle does not happen. In park, it jumps and drops from 1k to 2-3k. I cleaned the fast idle valve, but that didnt help. Is there a way to check and see if the valve is bad? I couldnt see inside it very well. I think it probably needs to be replaced, but wanted to check and see if it could be repaired before I spent any money.

3. I have tried to get VTEC to kick in 4 times. At about 40 MPH or so I floor it to get to the VTEC RPM engagement point which is like 4800 I think?!?!? The engine wont rev past 4500 rpm's. It seems like rev limiter kicks in. It goes back and forth spiking from 4400 to 4500 RPM's until i let off the gas, then it shifts back into regular gear like its supposed to once I let off the gas. When it spikes from 4400 to 4500 RPM's, I have certainly heard the engine "POP" like a backfire kind of sound 2 out of the 4 times I have done it.

The car has no check engine lights on at all. I did a new timing belt, water pump, thermostat, and complete tune up before the motor went in.



Any thoughts?