ignition timing question

[jonbill]

Try the green 'add files' button. 

[Zed Head]

If the files are on Google Drive you'll need to change the access from private to public.  Google Drive is surprisingly hard to use, not very clear.  Right click on the image, click "Share", then change the setting under "Get link" to "anyone with the link" by clicking the tiny black triangle on the right.  Very convoluted.

If you're on a Windows computer you can copy the image to the Clipboard and just paste it directly in to a post.

Or, you can save the image as a file on your computer and "choose file".

[Zed Head]

23 hours ago, Zed Head said:

Does timing advance when you rev the engine and the light is on it?

I'd put the timing light on it and make sure you know the distributor is working right.  I just remembered going for a test drive many years ago with a friend right after he did some work on his truck's engine, and he remarked that the engine seemed like it had lost power.  We were climbing a small dirt hill at low RPM.  I said it felt like the timing was retarded and he realized that he had left the vacuum advance hose off.  Put it back on and the pep came back.

Might be that you don't actually have any advance mechanism happening so you need 25 initial just to make it run half-decent.

[tzagi1]

[jonbill]

its normal to run well or better with that sort of ignition advance at idle.  I run 24° advance at idle during warm up to keep the revs up. 

The cam timing isn't really involved in how much ignition advance the engine wants. it might be involved in running like crap, but I'd ignore the cam until you've confirm the things the guys have mentioned.

1. confirm the engine really is at TDC when the pointer/pulley say TDC

2. check the vacuum advance works

3. check mechanical advance works

4. check what 'all in' ignition timing you have with a timing light (and no vacuum advance) 

 

[Zed Head]

13 hours ago, jonbill said:

I run 24° advance at idle during warm up to keep the revs up. 

That's a setting in the software though, right?  Can't remember your system, but you have electronic timing control?

The verification of what's happening during driving is the key though, as you suggest.  Get those numbers.

[jonbill]

10 hours ago, Zed Head said:

That's a setting in the software though, right?  Can't remember your system, but you have electronic timing control?

The verification of what's happening during driving is the key though, as you suggest.  Get those numbers.

Yes, it's a Speeduino ECU. I wasn't suggesting it as a solution, just evidence that the engine likes a lot of advance at idle. 

[tzagi1]

The mystery might be solved, zed head hit the nail on the head, the vac advance pot is doa., I did remove the cam sprocket and it was on position 3 and retarted, I placed the cam on pos 1 and the timing mark came back to the center. the car idles better and seems pepier off the line. checked timing and its on 28 advance, mechanical advance works and it seems to add another 20 degrees or so.

Any idea wher to find the vac advance pot?  it seems that they are totaly NLA.