How to find top dead center

Hi,

If you are just trying to locate TDC with the engine together, on the crankshaft pulley, there is a notch. It needs to be aligned with 0 degrees or TDC on the indicator located on the timing belt cover. I attached a pic.

If you are replacing the belt or trying to install the distributor, let me know. With the timing belt cover off, you need to use different marks, so let me know if that is what you are doing.

I hope this helps.

Take care,
Joe

Hi,

You will need to have the crankshaft on TDC and when installing the distributor, the rotor should point at where the number 1 spark plug wire will be in the distributor cap. Here are the directions. I attached a picture and circled the number 1 spark plug point on the distributor cap.

_____________________________

REMOVAL

1. Remove high tension leads.
2. Disconnect wiring harness.
3. Turn crankshaft to #1 cylinder TDC.
4. Remove mounting bolt and lift off distributor. Do not turn engine while distributor is removed.

INSTALLATION

Install in the reverse order of removal and note the following:

1. Coat the O-ring with engine oil.
2. Ensure that #1 cylinder is at TDC.
3. Align distributor drive blade with slot in camshaft.
4. After installation, adjust ignition timing (see Adjustments).
5. Tighten mounting bolt to 14 - 19 ft lb (19 - 25 Nm).

______________________________

Once installed and the engine starts, you will need to fine tune the timing. You will need a timing light to do this. Here are the directions. The last two pics correlate with these directions.

1993 Mazda Protege L4-1839cc 1.8L SOHC
Ignition Timing
Vehicle Powertrain Management Emission Control Systems Adjustments Ignition Timing
IGNITION TIMING
PREPARATION

Diagnosis Connector
pic 2

1. Warm engine to operating temperature.
2. Turn all electrical loads "OFF."
3. If using Mazda System Selector (SST #49 B019 9A0), connect to diagnosis connector. Set switch "A" to position "1" and test switch to "SELF-TEST" position.
4. Connect tachometer and timing light.

NOTE: If Mazda SST is not used, install a jumper wire between diagnosis connector "TEN" and ground terminals.

ADJUSTMENT

Timing Adjustment
pic 3

1. Following preparation, check if timing mark (yellow) on crank pulley is aligned with mark on timing belt cover:

5° ± 1° BTDC

2. If adjustment is required, loosen lock bolts and turn distributor as needed to align timing marks.
3. Tighten lock bolts to 19 - 25 Nm (14 - 19 ft. Lb).
4. Following adjustment, remove SST or jumper wire.

____________________

I hope this helps. Let me know if you need anything.

Joe

Yes. The 0 indicates TDC (0° before or after TDC). You will notice there are numbers with degrees both before and after the 0. When you use the timing light, that notch will light at some point on the cover. Then you can move the distributor one way or the other to achieve the correct timing. The procedure indicates 5° BTDC. That means the spark plug will spark 5° before the piston actually reaches TDC.

I hope that makes sense. Please feel free to let me know if you have other questions.

Joe.

Hi,

I have no way to reference that without being there. It isn't something listed in a manual. If I had to guess, I would say it will be near 22mm.

Joe

Hi,

If you are only replacing the sensor, there is no need to worry about timing. The sensor reacts to a toner ring that isn't adjustable, so the engine timing can't change that.

Simply remove the old one and install the new one.

If you look at the attached pic, it provides the directions specific to this vehicle for sensor replacement. Also, here is a link that explains in general how it's done:

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

Let me know if this helps or if you have other questions.

Take care,

Joe

See pic below.