Ignition timing problem part II :( need help.

Hey guys, so this is the story. 99 Nissan Altima with 49,000 miles, failed the functional part of the smog test in CA because the ignition timing was

12 degree BTDC. The correct timing is 20 degrees.

So I decided to fix it my self. The shop manual I have says that the first "mark" from the bottom of the pulley is the 20 degree mark so I set it to that. When I drive the car the engine sounded harsh under acceleration, so I moved the distributor and got the "mark" aligned to the 2nd mark from the bottom which seems fine, but the book claims that the 2nd mark from the bottom in 15 degrees. I really don't know what is wrong. One thing that I did realized later on is that I am suppose to disconnect the throttle Position Sensor before I take a measurement with the strobe light. I didn't do that, do you think that could be my problem? How much of a difference will that make? Please help, I'm getting frustrated by this fairly new car. The bumper to bumper warranty on this car is 3/36, but the powertrain is

4/60, which is still valid. Will this problem fall under the powertrain warranty?

Thanks in advance. :)

Reply to
elmo
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Not disconnecting the throttle position sensor can make a big difference. The engine control unit will advance or retard the timing based on a number of factors including throttle position. When you do the timing adjustment you are creating a base-line from which the ECU will then do its own adjustments, and it is critical that you follow the manual very carefully when doing this.

Could it be that the timing was actually correct, and that the smog-check place also should have disconnected the throttle position sensor but didn't?

I would th>

Reply to
Randolph

If the engine puuls roughly, its a sure sign the timing is too far advanced for the octane despite knock-sensing retardation. Whats the fuel quality like?

20 degrees at idle sounds too much Cab imagine some engines running 12 or perhaps 15, but no more.

Jason

Reply to
Jason James

Obviously, it's where the smart people hang out.

:)

Reply to
Stephen Bigelow

To piss people off?

mike hunt

"Philip" wrote:

Reply to
MikeHunt2

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