So I have a 99 civic and i cant seem to figure out what is wrong with it. It drives fine and still runs great. But the problem is with starting. If i have a FULL tank of gas it starts right up. But the lower the fuel tank gets the longer it takes to start. So if im at half tank it will take about 5 seconds of cranking over to start and if its close to empty it can take 10. The less gas in the tank the longer it takes. This is all after it sitting over night. If i run it to E and restart it it will start right back up.

I have already replaced:

Fuel pump
Fuel filter
Fuel solenoid
gas cap

I also ran some chevron techron fuel system threw it in my last tank of gas which didnt help at all either.

I have not hooked anything up to the fuel system to test pressures.

Any suggestions to what may be wrong?

 

Normal from what I have seen with the stock fuel pump.

 

You can try priming the lines by clicking the key on and off a few times before going all the way to crank. There is a check valve in the pump that is supposed to keep the gas from draining back into the tank while the car is parked but it doesn't always work that well.