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Matt, Mechanical Engineer
Category: BMW
Satisfied Customers: 22737
Experience:  BEng hons Mech engineering, in auto industry 22 years
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i have had a new dual mass fly wheel & clutch fitted to my

Customer Question

i have had a new dual mass fly wheel & clutch fitted to my 2008 318d E90, now it won't start. Turns over, but won't fire.
Submitted: 3 years ago.
Category: BMW
Expert:  Shantal-Mod replied 3 years ago.
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Expert:  Matt replied 3 years ago.

there are a couple of variants of flywheel out there
and the issue will be that the toothed wheel on the back of the flywheel that the crank sensor points at

the rise and fall of the tooth as its passes over the sensor generates a signal that the ECU turns into engine speed and on the toothed wheel there's a missing tooth to show where top dead centre is

if this missing tooth is in the wrong place then the ECU will be firing the coils / plugs and fuel injectors at the wrong time

so I'd suggest taking a look at the original flywheel and then compare the toothed wheel to the one that was fitted.
if the flywheel matchs, the other possibilty is that the dowel for the crank to the flywheel hasn't been fitted and the flywheel has been bolted up in the wrong spot

and one other possibility is that the crank sensor was damaged during the new flywheel fitting
Expert:  Matt replied 3 years ago.
do you still need help with this?