Eccentric issues.

[Jesus Freak]

My dually was having some kind of air intrusion issue, I could see more air in my sight glass than usual and I could see the bubbles ever so slightly. It also appeared as though I was having a bleed back thing going on as well. So I swapped out my mechanical fuel pump with another one I had, used but good, just a spare just in case, you know. Anyway, I had to mess with this and that and some how or another I got it I think, but that's no worry. The curiosity is that sometimes when you're fixing one thing you catch sight of another thing and that's my deal here.

The fuel pump I pulled out probably has a compromised check valve causing a slight bleed back but the real problem, or I might say what might be a problem is that the place where the eccentric moves the lever is scratched and gouged a bit. I'm going to get a new pump and put it in sometimes soon and see if the used but good pump I put in is scratched up.

What do you think? It's tough to get a picture and I don't have a nice hand model like @Cant Write .

 

[david85]

Mine looked the same when I replaced it. I was actually relieved, because it seems to explain where the metal shavings on the magnetic drain plug are coming from.

 

[Jesus Freak]

Mine looked the same when I replaced it. I was actually relieved, because it seems to explain where the metal shavings on the magnetic drain plug are coming from.

So you recon that the eccentric is okay in the engine? FYI, the eccentric is the technical name for the spinny lobe thingy.

 

[IDIBRONCO]

So you recon that the eccentric is okay in the engine?

Looks normal to me. I think that the eccentric is made of harder metal that the lift pump arms are. If you're really worried about it, you can use some latent yoga skills and maneuver a mirror and a light into the area where the lift pump goes and get a glance at your fuel pump eccentric.

FYI, the eccentric is the technical name for the spinny lobe thingy.

I thought that is a camshaft. It has a lot of lobes and it spins just as fast as the eccentric does. So, technically, the cam lobes spin MUCH faster that the lobe on the eccentric does when you combine them all together. About 16 times faster.

 

[Jesus Freak]

Looks normal to me. I think that the eccentric is made of harder metal that the lift pump arms are. If you're really worried about it, you can use some latent yoga skills and maneuver a mirror and a light into the area where the lift pump goes and get a glance at your fuel pump eccentric.

I thought that is a camshaft. It has a lot of lobes and it spins just as fast as the eccentric does. So, technically, the cam lobes spin MUCH faster that the lobe on the eccentric does when you combine them all together. About 16 times faster.

The ones I've pulled out have been smooth maybe a shiny spot, but this has grooves. My concern is that the eccentric is stuck and actually working like a cam lobe instead of rolling. My thoughts were if I pull the other out in a week or two and it's grooved or damaged I might make the move to a Holley black and a regulator. I'd prefer the mechanical pump though.

 

[Austin86250]

Your phone camera is a lot easier than than the mirror method, this was the only picture I could find in my camera roll in a timely manner but you can see it a lot better

 

[Jesus Freak]

Your phone camera is a lot easier than than the mirror method, this was the only picture I could find in my camera roll in a timely manner but you can see it a lot better

Fasinating! I wasn't even going to try to look. When I pull the other pump out it should let me know what's up.

 

[Austin86250]

Fasinating! I wasn't even going to try to look. When I pull the other pump out it should let me know what's up.

I was going though fuel pumps every2-5k miles on a bad eccentric new eccentric haven’t had an issue in 7k

 

[IDIBRONCO]

My concern is that the eccentric is stuck and actually working like a cam lobe instead of rolling.

Well your concern is founded, but 100% wrong. The eccentric spins with the cam. It doesn't roll. It's held in place on the cam by a key way so that it doesn't spin. All fuel pump eccentrics are held in place. If they spun, then they wouldn't activate the fuel pump. On first gen 7.3 PSDs and (I think) 6.2 Chevys, it's actually cast as part of the cam and can't be replaced.

 

[Jesus Freak]

Well your concern is founded, but 100% wrong. The eccentric spins with the cam. It doesn't roll. It's held in place on the cam by a key way so that it doesn't spin. All fuel pump eccentrics are held in place. If they spun, then they wouldn't activate the fuel pump. On first gen 7.3 PSDs and (I think) 6.2 Chevys, it's actually cast as part of the cam and can't be replaced.

So it's not like one on a gas motor that has like a outer shell that spins?

 

[Rdnck84_03]

So it's not like one on a gas motor that has like a outer shell that spins?

No it just functions like a cam lobe.

James

 

[Jesus Freak]

No it just functions like a cam lobe.

James

Well, if the next on is gouged up I'm going electric. DANG!!!

 

[Rdnck84_03]

The eccentric is replaceable, but it is pressed on the cam instead of bolted to the front like a gasser.

James

 

[Austin86250]

Here’s to cams with the eccentric, spacer, hold down plate, and gear pressed off of course I don’t have A picture of the pressed parts

 

[Jesus Freak]

The eccentric is replaceable, but it is pressed on the cam instead of bolted to the front like a gasser.

James

I'm not interested in marrying a job like that right now. I've been kinda wanting to experiment with a Holley black and a regulator.