Truck entered our shop with low compression on cylinder one due to a broken follower guide. The cam followers on cylinder 1 turned sideways and wiped out the cam lobes. We replaced the cam and followers, updated the front cover, and due to the engine hours and cylinder condition put a works kit in (pistons, liners, bearings.) The engine sensor harness and injector harness were also replaced due to broken hardshell connectors. We replaced the IDM bottom half due to Cylinder 1-6 circuit fault codes. Other than the misfire on cylinder 1, engine ran decent when it entered the shop.

Now here's the problem: Engine is reasembled and will not start. It sets a code 147 incorrect CKP signal signature. RPM signal toggles on and off as you crank, (like ever other second.) New CMP and CKP made no change. All wiring checks to both sensors pass. Tried ECM from another like vehicle made no change. Used a dial indicator to verify valve timing. Crankshaft is at TDC mark just as intake valve on cylinder six is opening. Scoped both CKP and CMP signals and compared to like vehicle, both look good and match like vehicle.

Any ideas?

Kim Scheidel
Owner/Technician
Scheidel's Fleet Service
Sacramento, California, USA