The stumbling upon start-up after changing the fuel lines is understandable...
The IP is just "Bleeding" out all the air left from breaking the fuel system open,
AND an air gap/pocket or two left over will cause the stumble.The IP is "Self
Bleeding" ,that's why it corrected by itself.

If air is causing the extended symptoms,you may have a problem with a fuel
line connection (or fuel line cracks) between the fuel sock in the bottom of
the tank and the IP.
OR there's an air leak allowed between the hard metal fuel line capnut(s) and
and Injector or the Delivery Valve of that line on the IP.
Logically,If you had an air leak with a hard metal fuel line... you'd also have
fuel leaking when the engine's running.


YES,by all means check your Timing Chain wear/stretch (prudently every
133,000 kilometers) There are instructions for the DIY on this forum.

__________________
'84 300SD sold
124.128