1986 GMC Sierra fuel mechanical pump mystery
 

My truck (1986 GMC Sierra C2500 with 7.4L) had issues with starting, so I checked the fuel system, and I found the mechanical fuel pump isn’t working. This is a brand new installed 2 months ago by a garage. So I removed it and I installed a new one.
So I compared both fuel pumps, and I found out that the one I removed is missing a spring that is between the pump lever and the housing, I checked the cavity (where the fuel pump is fit, and where the rod is) and it’s not there.
What is strange is the truck was running when it came from the garage? 🤔
Is that normal? Or I’m missing something? 🧐