Hi Tx,
An easy way to see if the element is still servicable is to assemble the whole thing after cleaning thoroughly, then with the rack in the full open position, pop it back onto the machine, hook up the supply line. Don't worry about the timing at this point. Pop off the check valve on top then spill bleed it to get any air out. Screw the check valve back in and turn the motor over slowly by hand.... If hardly any fuel squeezes past the check valve while creeping it over, the element is likely shot.... The small amount of back pressure the check valve creates is enough to show if the element is unable to seal properly....
All of this is of course assuming you have reasonable filter condition and there is a minimal, but positive pressure of fuel to the IP... And, most importantly, you havent unscrewed the IP tappet to excess...
No special tools required, no finicky measuring, and, the bonus is, once IP function is confirmed this way, at creep speed, it pretty much has to work at a normal running speed.... Don't mess with the timing if you can help it.... If it was running before, it will run again at the current setting unless of course, the timing bolt came loose and unwound itself somehow... One thing that is worth checking while u have the element out, is the top face of the element piston. If there is about a 1mm ring around the top periphery or crown, it might be indicative of the piston being pushed up too far by the tappet. If that is the case, take care and back off the timing bolt before you go any further... Occasionally, when the element wears, you have the symptom of the timing retarding a bit... Guys often mistakenly advance the timing a bit and the unit runs fine for a while, albeit with a bit of an intermittent excessive diesel knock that is hard to track as to why.... Effectively you can come very close to bottoming out the pump when you start advancing the timing, bottom out the pump, and things give way catastrophically.... Don't go there!!
I have an element lying around here that was bottomed out, if you want, i can take a couple of pics for you so you can see what to look for....
Hope this helps...
Regds
Ed