I am doing some work on my '93 12V motor for my 2wd to 4x4 club cab build.
I pulled the tamper proof screw cap off the virgin, original VE pumps fuel screw on the motor today. The collar was bottomed right out against the jam nut on the fuel screw.
So, I backed the screw out and carefully removed the collar. I then got the jamb nut to back up the threads smoothly with some pick work and time.

I thought I would install the fuel screw back in less than a turn more than stock and save the real pump turning for once it was in the truck.
I got it back in and tightened down to the stock location again no problem.
I felt light resistance trying to get the extra turn, I would say less than 1/8 of a turn extra and felt it. I stoped there and have been researching if anyone else has had this issue.

I haven't found much in the sticky and such, but know each pump is different. Maybe I am at full fuel screw adjustment in stock form on this auto '93 pump?
Before I removed it, the collar was at the very end of the fuel screw and there where no screw threads exposed behind it.

Any thoughts DTR'ers?

 

my 93 w250 with getrag was same way, I couldn't get even 1/8 turn on it..trucks no slouch so...

 

Compounded manufacturing tolerances are probably the reason. When a fuel shop tunes a pump, they twist the screws until it delivers whatever volume and pressure is spec'ed. Where the screw thread lands is not important.

I believe there's more screw adjustment on a non-IC pump... to the point you can adjust it to runaway. This is probably one of the reasons there's less thread/adjustment on the IC pumps.