Fmi 157 spn 18

[SquareOne]

(08-21-2020 )Hallmanhauling Wrote:  How bout if I replaced just the fuel pump head and not the rollers as well with it?

Hmm, that may be an issue. I wrote about this topic on here awhile back with my curiosity into the pump failures on these engines. Basically I wanted to know which came first...the chewed up cam/rollers or the plunger issue?

Unilevers ( like Mr. Hagg, another very knowledgable/respected member here ) had mentioned that the updated rollers come with a DLC coating on the pins which secure the rollers and allow them to rotate. The pins IMO seem to be the issue. From the limited pics I had seen of failures, it looked as if the roller pins would wear and cause the rollers to 'skip' along the lobes of the cam shaft thus causing major chewing of those components.

My original question (when the ceramic plungers were the supposed issue) was this -----> Was the erratic behavior of the failed roller and condition of the cam lobe the REAL cause of the ceramic plunger debacle?? In that instance, the real culprit would be the (now updated) pins which secure the rollers.

If that were the case (just speculating of coarse), then I would have to assume you wouldn't have a leg to stand on since that component was not replaced...only the head. What is the mileage on the engine? Are those the original rollers in that fuel pump?