I have 91 D250 with IC & OD, with 200K miles. I recently changed the Fuel/Water filter, and battery concurrently. It is not my driver, so sat for a while during very cold weather for Calif where I live. I bled air from lift pump, & individual injectors, still would not start. Tapped on KSB valve with box end, and engine almost fired. Loosened the solenoid, engine fired, ran rough but smoothed out. Tightened solenoid back up, truck ran, started daily for 4-6 days. Been sitting now for 5 days, will not start. Now it is bitterly cold here, hi 20's to lo 30's. Cannot find a KSB solenoid, Chrysler part # 4638937, discontinued by Dodge. Dealer price was $505.00. Finally found a pump shop who had the solenoid for $240.00, but told me that is not the problem. Stated that the KSB solenoid has nothing to do with running.starting. He said the fuel solenoid is what I need, unless when I remove the fuel solenoid there is metal pieces on the plunger, then rebuilt pump.
Does anyone have an answer for me? Thanx