starting problems

[2.4 durashift 2003]

hi.
i fit new flywheel, new clutch and new starter motor in my van 03 reg 2.4di lwb.
now my problem is sometimes the starter motor don't turn (just selanoide noise). in 10 times 3 or 4 don't turn. Jump start with leads, fine. today i change batterie (put stronger one) but i still have the same problem. now in 10 times 2 or 3 don't turn starter motor.

when i put jump leads always turn and start

anyone can help me?

Faulty starter motor?
thanks

[MrMPuk]

Bad connections on the starter or bad earth to the engine maybe.

[Nighthawk]

i'd go with poor connections too, sounds like the vehicle is using the slave vehicles electrical system to run the starter.