On Saturday afternoon we had a phone call from a customer based in Colchester. This customer had a Ford Transit who just had the engine changed. The customer required the issue to be coded along with the injectors and all fault codes to be cleared. The customer was refitting the van back together and wanted the van working for Monday morning so we attended the van Sunday afternoon at the customers request. Upon arrival we ran a self test with a Ford IDS diagnostics and discovered CKP fault this fault relates to the crankshaft position sensor the sensor was moved from one flywheel to another flywheel and this led to the starting issues of the van. As there was no valid crankshaft position the van would not start and this fault needed to be addressed any others. We provide the customer with the diagnostic print out and advised the crank position sensor was changed.