Just realized my injector cups were the real problem

Had a 6.0 Powerstroke that kept missing under load for months. Chased injectors, harnesses, FICM voltage - the whole deal. Finally pulled the cups after 3 tries and saw micro cracks around the O-ring seats. Put new cups in and it ran like new the same day. Anyone else skip inspecting cups and regret it later?

3 comments

3 Comments

oscarc121mo ago

Happened to me on a 7.3 actually. Ran fine cold but once it warmed up it would start stumbling and I was ready to pull the whole injection system. Fought with it for THREE weekends before I finally took a flashlight and really looked at the cups. Saw tiny hairline cracks right where the O-rings sit. Swapped them out and it was like a different truck. Its amazing how much trouble those little cracks can cause. Definitely not something to skip checking.

anderson.piper1mo ago

Three weekends? I feel less bad about the two weekends I wasted cussing at my own truck before I found the same thing.

victorh811mo ago

Three weekends is rough, man. I had mine do the same thing on a 6.0 a couple years back. Would run fine cold but after about 20 minutes of driving it'd start stumbling like crazy. I went through two sets of injectors and a FICM before I finally checked the cups with a good light. @oscarc12 hit it right on the head, those micro cracks are sneaky. You almost need a magnifying glass or a strong LED flashlight to see them. Once I swapped the cups out, it was like a completely different truck. If anyone is fighting stumbles or misfires and everything else checks out, don't skip looking at the cups. It's a cheap fix that saves a ton of headache.