air bubbles in inline fuel filter

[bpeters2]

85 300td: There is numerous air bubbles in my inline fuel filter. When I rev the engine it gets worse and is almost like a foam, when you return to idle tohe foam also gets better. I should note, that this car has a frybrid WVO conversion, so the diesel has numerous connections which could be "leaky", do airbubbles indicate a air leaks in the fuel system?? thanks for the help