Setting TDC with megasquirt.

[Shadow]

Hello.
I was curious about how close my timing advance is, and
decided to set the "true" timing.

Well it was a failure. The way I understood it, I have
to light up the 0 | T mark to the jut on the lower
timing chain cover while idling.

I first started the motor and put the timing light pick up
on #1 cyl, and adjusted the MS for both marks to line up.

I had to put in 77* for the lines to match up which made the
map sensor read 50kpa from 38kpa at 60*. Doesn't seem right. To me it feels like it actually retarded it.

Higher numbers moves clockwise.
Lower, counter clockwise. Let me know if this sounds right to you guys.

My idle advance is 22* and idles strong.

The engine is a M30b35 btw.

[turbodan]

Were you expecting a lot of manifold vacuum while running zero ignition advance?

[Shadow]

I don't understand what you mean.

[Shadow]

ok, so are you saying I was doing it wrong,
and I was supposed to set idle advance to 0*
(or crank advance angle).

Then adjust the trigger angle so the lines match up?
That makes sense.

I was just going off of what a friend was saying.

which makes sense since if my idle is 22* then it'll be firing
about 22* off the TDC mark when running.

[russc]

Ya,
If the system is right, then if you set idle advance to fixed, set to 0deg then adjust the trigger to get 0deg. That sounds right to me.

I think what Dan said is where you expecting something other than what you got? Do you know what the vaccum should be at a paticular idle speed and 0deg advance? Im pretty sure I don't. I guess its just a guess what it should be.

RussC

ok, so are you saying I was doing it wrong,
and I was supposed to set idle advance to 0*
(or crank advance angle).

Then adjust the trigger angle so the lines match up?
That makes sense.

I was just going off of what a friend was saying.

which makes sense since if my idle is 22* then it'll be firing
about 22* off the TDC mark when running.

[Shadow]

Gotcha.

Just wasn't thinking about what's actually going
on in the engine.

Was focused on the "Line up the marks while at idle".
I'd guess kpa would be like 80 trying to idle at 0*.

Thanks for the response, just lack of thinking on my part.
I think my true timing is about 5* too retarded. I'll post tomorrow
if you guys are interested.

[turbodan]

I'm saying you should expect weak manifold vacuum with no ignition advance.

Its pretty easy to get dialed in. Like you said, zero out your ignition tables so its firing the spark where it believes TDC to be. Then you adjust your trigger offset until the timing marks line up.

[Nebraska_e28]

You can check Duke's cardomain site on setting this, it may shed some light for you.

[Duke]

You can check Duke's cardomain site on setting this, it may shed some light for you.

Thats where he got that picture or from the Tech FAQ forum.

[Nebraska_e28]

You can check Duke's cardomain site on setting this, it may shed some light for you.

Thats where he got that picture or from the Tech FAQ forum.

I thought it looked familiar, I must be getting old.

[Duke]

I must be getting old.

Yea LJ, you are old as hell...........................whatever

[FirstFives Dictator]

I'm saying you should expect weak manifold vacuum with no ignition advance.

Its pretty easy to get dialed in. Like you said, zero out your ignition tables so its firing the spark where it believes TDC to be. Then you adjust your trigger offset until the timing marks line up.

Every version of MSextra that I know of has fixed timing setting so you don't have to change your spark table

It's in different places; MS1Extra vs. MS2Extra