Shudders Momentarily at Idle

[Blue&WhiteStroke]

I have a 97 7.3 with 5spd and 112,000 miles. I had a starting problem earlier this year and replaced all glowplugs and put in a Stancor relay. Also did injector o-rings and they were shot, since then it has ran great.

It has been getting below 0 and its still starts fairly well but a few weeks ago I noticed when the truck is warm and i let up on the clutch it drops down to idle and shudders for a second or two then comes out of it and idles better.

Wondering about FPR spring getting week or the FPR screen. Not really that big of a problem but was wondering what input you guys would have?

Thanks