Crank Angle Sensor

[911/Q45]

I'm reassembling my 90 Q engine after timing chain guide replacement and valve and front covers removal. How can I be sure that the Crank Angle Sensor is correctly installed and not 180° out? Also, is TDC for #1 cylinder when the cam lobes are outboard or inboard when looking down from above?

[Q45tech]

You have marks on the cam gears and crank gears and special colored links on the chain that must be aligned correctly.The crankangle sensor will only go in one way [real pain to wiggle and find the spot] ..... the adjustment bolt should be positioned so that the left part of the slot is 2/3 open to the left then the bolt, then about 1/3-1/4 open space to the right......this will get you close to 10-15 DBTDC.

[911/Q45]

I never disconnected the chains and I didn't touch the crank sensor adjustment bolts, just unbolted the assembly from the front cover and pulled it out of the front of the driver's side exhaust cam. This shouldn't make a difference if it only fits into the cam end one way, correct?

[firedane]

I looked in the owners manual and took the front cover off of the unit. It showed a small dot on the center rotor and the sensor. Also, it shows the rotation of the sensor. There are slots around the center rotor. Number one is a double slot. When installed the double slot will be before the centerline of the sensor to correspond with the timing. Also, the drive tang has on mine has a small V mark that points toward the dowel pin on the camshaft.

firedane

[911/Q45]

That's the info I needed Firedane, thanks. Now I just have to worry about antifreeze, oil, fuel and vacuum leaks in inaccessible places when I fire this thing up again!