Strugglin To Start

[escorttdi]

ive got a 56 galaxy tdci...... its turning over fast but takes ages to start

there was a lot of air in deisel so changed the fuel filter housing top part

put 2 glow plugs in.. the middle 2 as the other 2 are ridicoulys hard

ive a temp control sensor to put on as it might be that was told

ive also been told to clean egr valve could be carboned up

also been told could be crankshaft sensor

been told it might be valve on top of tank

anybody had same problem???????????