Ignition timing question

8428 Views 7 Replies 4 Participants Last post by graelich, Mar 1, 2012

graelich

Discussion Starter · Feb 29, 2012

I'm trying to set the ignition timing on my 1996 Corolla 7A-FE after changing the distributor. I've never done it before, and I have a question:

As I understand it, you use a timing light to align the notch in the edge of the crankshaft pulley with the 10-degree mark. So that you can see the notch when standing in front of the car, the crankshaft pulley is slightly wider than the small block with the timing marks, and the edge of the pulley extends slightly beyond (to the left of) the end of the block. (This is what the illustration in the Haynes manual shows.)

In my car, however, the crankshaft pulley is slightly narrower than the block with the timing marks, so that the notch in the edge of the pulley is hidden behind the block, making it impossible to see the notch when standing in front of the car. The only way to see it would be with mirrors or an endoscope, or by removing the engine from the car. Which makes it impossible to set the timing.

Am I missing something?

graelich

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aballl18

· #2 · Feb 29, 2012

You need to get a timing advance light that has a knob or display were you can input the desired timing and align it with the 0° timing mark.

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graelich

Discussion Starter · #3 · Feb 29, 2012

Thanks, but align *what* with the 0 degree timing mark?

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aballl18

· #4 · Feb 29, 2012

there should be a marking on the balancer and when you flash the light you should see a little white light show up and as you advance an retard it it should move also. I might be wrong but the pcm controls the timing so just as long as you didnt change anything in the engine you should not need to time it.

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ganda1f

· #5 · Feb 29, 2012 (Edited)

aballl18 said:
...but the pcm controls the timing so just as long as you didnt change anything in the engine you should not need to time it.

That depends on the kind of distributor that is in the car. This being a 1996, there is a fair chance that it has the non-adjustable variant. It has just one position where the screws can be tightened. In which case the ignition timing is controlled by the computer (ECU)

You could always grind down the plastic block with markings a little. Or look slightly from the side. It does not really matter as long as you can see the notch in clear relationship to the markings.
Put a dab of paint on the side of the pulley, where the notch is, so it will be easier to spot.

And the timing should be aligned with 10-degree mark with TE1 and E1 terminals jumpered in the diagnostic connector.

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graelich

Discussion Starter · #6 · Mar 1, 2012 (Edited)

Thank you, Ganda1f. I think you just answered an unanswered question from another thread, namely, whether I even need to check the timing after replacing the distributor. As I observed in that thread,

"When the distributor is correctly aligned and (loosely) bolted down, there is very little play at all--maybe 1 mm, or less than 2 degrees, which is 20% of the spec (10 degrees BTDC)." I'd actually say it was a bit less than a millimeter. Unambiguously, however, the hold-down bolt holes in the distributor and the engine are both circular, and the one in the distributor is only very slightly larger than the bolt itself.

Does that mean I have the nonadjustable type?

P.S. Putting paint on the pulley is a good idea, too.

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