Pro tip: check your lift pump before you throw parts at a no-start

Spent 3 days chasing a crank no-start on a 2005 Duramax last month. Swapped injectors, new CP3, even had the ECM flashed before I finally tested the FASS pump at idle and saw 4 psi instead of 15. Anyone else get burned by a dying lift pump that still whined like it was fine?

2 comments

2 Comments

dianal9420d ago

My buddy Mike on a 2002 7.3 Powerstroke spent two weeks swapping ICP sensors and doing a full injector harness before he noticed the lift pump was barely humming at key on. It was making the right noise but putting out like 3 psi and his truck would start after sitting for an hour but die under load. He finally borrowed my fuel pressure gauge and it took him less than five minutes to find the real problem.

jordanc3220d ago

That "whining like it was fine" part is the real killer because the noise tricks you into thinking the pump is doing its job. What I'm wondering is did @dianal94 your buddy ever figure out if the pump was slowly dying or if it just dropped off a cliff one day? Seems like those FASS pumps can fool you with good sound right up until they flatline on pressure.