First and formost, WELCOME to the forum!
what year is your 240?
the squeak is normal, it's the sound of the fuel squirting through the filter into the return line. it means you have full fuel.

how long do you let the key sit in the glow position before you attempt to start?
how cold is it where you are?
when was the last time the valves were adjusted?

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!