"89 300 zx

Maintenance/Repairs
1

I found top, dead center in my '89 nissan 300ZX by manually turning the crank and using the removed #1 spark plug. having done that, I discovered that the rotor is not pointing to the #1 spark plug wire and the timing belt marks do not line up. How can I fix this problem? Any help would be greatly appreciated. Thanks

2

Are you sure you’re on the compression stroke and not the exaust stroke? How far off are the timing marks?

3

Ditto to what Texases said. The mark comes around twice in the piston’s cycles, once at the top of the compression stroke when the plug should fire and again at the top of the exhaust stroke/beginning of the intake stroke when the rotor should be 180 degrees out of phase.

Realize too that the marks will not line up exactly. Your timing will typically be somewhere about 6 degrees before TDC (check your tuneup specs).

4

If possible, use the timing mark on the crankshaft damper to find TDC by turning the engine by hand until the mark points at zero, or zero points at the mark.

Tester

5

I used the timing mark on the crankshaft damper to find TDC by turning the engine by hand until the mark pointed at zero,I also used a straw in the #1 plug to determine the highest piston,the zero mark and the piston check out fine but I only see one timing mark in the middle,and the rotor points to the #5 plug.

6

I used the timing mark on the crankshaft damper to find TDC by turning the engine by hand until the mark pointed at zero,I also used a straw in the #1 plug to determine the highest piston,the zero mark and the piston check out fine but I only see one timing mark in the middle,and the rotor points to the #5 plug.

7

I used the timing mark on the crankshaft damper to find TDC by turning the engine by hand until the mark pointed at zero,I also used a straw in the #1 plug to determine the highest piston,the zero mark and the piston check out fine but I only see one timing mark in the middle,and the rotor points to the #5 plug.

8

Again, TDC of the compression stroke or TDC of the exhaust stroke?

9

Tdawg31, your doing it wrong. The piston will go up and down twice on each cycle, hence 4 strokes (down for intake (1), up for compression (2), down for power (3), up for exhaust (4)). You need to find TDC, the end of the compression stroke. This is done by placing a finger on the spark plug hole, and rotating the crankshaft. When the air blows out of the hole, the piston is on the compression stroke. When the piston reaches the top of the compression stroke, your at TDC. Then tell me where the timing marks are.

10

Thank you very much BustedKnuckles,great info,I’ll check it out and let you know.Thanks again.

         Tdawg31