Dancing Timing

[steppinthrax]

I have a 94 Nissan Altima. I recently replaced the distributor because it was leaking. I adjusted the timing according to the service manual. It told me to disconnect the TPS (Throttle Position Sensor) connector and rev the engine a couple of times. I adjusted it to 20 degrees and noticed while the engine was on and idling it stayed around 20 degrees. I then shut off the car and reconnected the TPS. I noticed then the timing kind of dances (doesn?t stay solid on 20 degrees). The engine sounds OK but is this normal....

 

[T2urtle]

are you doing this with a timing light?


your timing goes back and fourth when you rev it. But at idle it might dance +/- 1


what you did was right, its the general steps to have your timing set. 20 degrees? what is general specs? 20 is high i think, 10-15 is generally what i put it at... 17 max and only if your running 93 octane.

 

[steppinthrax]

Originally posted by: T2urtle
are you doing this with a timing light?


your timing goes back and fourth when you rev it. But at idle it might dance +/- 1


what you did was right, its the general steps to have your timing set. 20 degrees? what is general specs? 20 is high i think, 10-15 is generally what i put it at... 17 max and only if your running 93 octane.

Yeah I was using a timing light and underneath the hood there was a sticker there indicating the timing. There are more then one timing mark on my crank. However the 20th degree mark is the very last one. It stays on 20 degrees with the TPS disconnected. However upon reconnecting the TPS and re-starting the car the timing dances between the range of timing marks on the crank. However, I'm not getting any problems or engine idle issues....

 

[ValValline]

I assume the reason you disconnect the TPS is due to the fact the ECU will change the time on the fly while the motor is running. I am sure that is what you are seeing with it connected. Seems like normal operation.

 

[Toastedlightly]

20* may be the last one, but it may not be correct. The engine could be pulling timing on the fly to compensate

 

[steppinthrax]

Originally posted by: Toastedlightly
20* may be the last one, but it may not be correct. The engine could be pulling timing on the fly to compensate

The sticker underneath the hood (original sticker) indicates 20 degress BTDC

The Service Manual indicates 20 degress BTDC

There is a diagram of the crank with a readout of each mark and it's degree marking. Indicating that the last mark is 20 degrees BTDC

What are you talking about.