i have no 12v power to my lift pump. fuse is good relay is new pump is new. also no ground to pump.

Question

hello my 2000 chevy 3500 HD would not start. i have no fuel presure from lift pump. i rerplaced the pump,rerlay and fuse. it dosent have a ground at the pump eather. i have added a new ground to the pump. and hot wired the pump to get it started. then after it started and i blead the air out of the system. i unhooked the hot wire and it continued to run fine. but i want to know what the problem was in the begining. that was a couple days ago and i havent had any problems since.

Answer 1

This condition that you had is usually from the fuel pump control unit . When the outside temperature is hot. it creates a no start condition  If you where to check for code you would have a U0100 code set, You clear that code. then crank the engine not at a short crank but a long crank and the engine would start.