Losing fuel pressure

[scrobbyd]

Just installed a new Walbro 340 and for some reason it's losing it's prime. Each time before starting my car after it's been sitting for a while I noticed my fuel pressure gauge is on "0". Once I turn ignition on it has to reprime. What is the most common cause for my problem? Also after a couple 20 lbs of boost passes I can tell that it's starving for fuel. Because it will pop like a hose has blown off and sometimes car will even die. Any info?

Thanks in advance

 

[BlackBandit]

As long as your car holds its prime for about 30 minutes you're doing okay in that department. If not you need to figure out if it's leaking past the fp regulator, through the injectors, or back through the fuel pump.

As far as the starving for fuel "after a couple #20 passes," thing goes I would ask if it only does it after a couple of them or during the first one? If it's after a couple then it sounds like your fuel pump isn't up to par. Where did you get it?

 

[87geeinn]

Fuel pressure will slowly return back to 0psi as the car sits and cools down. That's normal.

Popping and dying under boost can be a number of things. With all those mods, I hope you have a scantool to monitor things. At the very least, you want to make sure it's not detonation that you are hearing. If it's loud like that, then you are about to lose a motor. On the brighter side, it can be a bad MAF, bad coil pack, ignition module, crank sensor rubbing on reluctor ring, etc, etc.

Need more info to help.

 

[scrobbyd]

FYI

Found the problem, short hose from sending unit to pump inside the tank had almost come completely off of the sending unit side. Cut a longer piece of hose and tighten the &@:$ out of the hose clamps. One more problem solved.