my 2oo2 dodge diesel dies when ideling , but will start up.some times it will be hard to start busually starts right up and keeps running.this usually happens after it warms up.it will miss some times and blow black smoke. I haven' driven it to far lately,because i'm afraid of getting left on the side of the road.Lift pump pressure is 13# at idle,8#underload. Could this be my vp44 going?,it has84k on it. HAS code 1693 and730 no check engine light.