Now we come to a very important part of what we're doing. That is, to get this Carrera back on the road again.
So since we are about done, it's about time to time the MFI pump to the motor.
The old belt had very low miles on it, but many years had passed. Always replace the MFI timing belt if the motor is old from mileage or from age.
This diagram showing the firing order of a Porsche 911 is here for those of us that need reminding, probably no one here.
Keep track of what cylinders are where. It makes life a lot easier when working on the motor.
Now the first thing that we do is move the crankshaft to TDC (top dead center) on the compression stroke of the number 1 cylinder.
To do this, move the front pulley so that the mark on the blower housing (crankcase seam) lines up with the Z1 mark on the pulley.
Make sure that the distributer rotor is pointing to the notch on the distributer housing (number one in firing position).
Next, turn the motor 360 degrees more until the Z1 mark lines up again with the crankcase seam.
Now we are at TDC on the exhaust stroke (cylinder #1), and about to start the intake stroke. This is also called overlap because the intake and exhaust valves are overlapping; as one is closing (exhaust) and the other is opening (intake).
Now turn the motor over just a little more until the FE mark on the pulley lines up with the crankcase seam.
The engine is now 40 degrees after overlap TDC/#1 and fuel will spray into the combustion chamber just as the intake valve is fully open. Awesome!
The other part of this timing procedure is the position of the drive pulley on the MFI pump.
There is a notch on the back of the MFI pump located on the coller that's on the housing.
It should line up with the notch on the aluminum drive hub that drives the MFI pump.
See detail in photo:
With everything in the right place, the belt slips on, and the MFI is now timed to the engine properly.
The belt still needs to be adjusted so that it is tight.
By tightening the nuts that hold the pump down and moving it away from the cam that drives it, the belt is tightened.
NOW LET'S PUT THAT MOTOR BACK INTO THE CAR! I WANNA DRIVE MULHOLLAND!
