Jump to content

3sgte unstable ignition


Toliski

Recommended Posts

Could be a few things.

1) if your trigger wheel is Cam mounted (replaces the distributor) it could be slop in the cam belt. 

2) it could be that your crank sensor is wired incorrectly (reversed polarity?) and is giving an unstable signal

3) it could be that your trigger signal is picking up noise from the engine bay and isnt providing a stable signal

4) if your timing light allows for advance correction and you either bump this dial while working or its too low an RPM for it to work correctly (ie while cranking). Set this to 0 advance if your light has it.

Can you please post a trigger scope capture while cranking (and at idle if you can start it), and a log of it running at idle if it will currently run+idle.

Link to comment
Share on other sites

17 hours ago, cj said:

Could be a few things.

1) if your trigger wheel is Cam mounted (replaces the distributor) it could be slop in the cam belt. 

2) it could be that your crank sensor is wired incorrectly (reversed polarity?) and is giving an unstable signal

3) it could be that your trigger signal is picking up noise from the engine bay and isnt providing a stable signal

4) if your timing light allows for advance correction and you either bump this dial while working or its too low an RPM for it to work correctly (ie while cranking). Set this to 0 advance if your light has it.

Can you please post a trigger scope capture while cranking (and at idle if you can start it), and a log of it running at idle if it will currently run+idle.

I still using the distributor.

The engine run and revving with out any problems except some miss fires at idle.

No corrections at timing light.

I always have that problem, before couple of days I open and rebuild my distributor and I gapped the magnets at Toyota specs (I don't replace the magnets only the sealing oring and the bearing) but don't change anything. 

Link to comment
Share on other sites

I can't be sure this is your problem but my feeling is your trigger 1 & 2 edges are a little too close for comfort, it could potentially result in clashing edges which will shift the timing by one tooth.  It appears closer at cranking speed than idle too.

Normally the Toyota trig 2 is nicely centered between the trig 1 tooth but yours is not for some reason.  I don't know what the distributor looks like inside but is there a way to move the sensors relative to each other?

Capture.png

Link to comment
Share on other sites

1 hour ago, Adamw said:

I can't be sure this is your problem but my feeling is your trigger 1 & 2 edges are a little too close for comfort, it could potentially result in clashing edges which will shift the timing by one tooth.  It appears closer at cranking speed than idle too.

Normally the Toyota trig 2 is nicely centered between the trig 1 tooth but yours is not for some reason.  I don't know what the distributor looks like inside but is there a way to move the sensors relative to each other?

Capture.png

Thanks Adam for your answer.

My English isn't very good.

Your suggestion is that or I must to check my distributor or I must to change it? 

If you are remember my dwell time is all over the place.

Link to comment
Share on other sites

You have noise level breaking through your trigger arming threshold.

You have this set to 0.3v on both your signals:

At idle crank the noise floor only very slightly above the 0.2 you are seeing I would raise this to 0.5 at 0rpm for both triggers

On Idle the noise floor maxes out at 0.5 which is above the noise level and may been seen as a trigger I would set the arming threshold to 1 at 1000rpm

As mentioned about the trigger points are near overlapping need to get this much more in the center.

 

 

Screenshot 2019-01-15 at 23.13.01.png

Link to comment
Share on other sites

11 minutes ago, ClintBHP said:

You have noise level breaking through your trigger arming threshold.

You have this set to 0.3v on both your signals:

At idle crank the noise floor only very slightly above the 0.2 you are seeing I would raise this to 0.5 at 0rpm for both triggers

On Idle the noise floor maxes out at 0.5 which is above the noise level and may been seen as a trigger I would set the arming threshold to 1 at 1000rpm

As mentioned about the trigger points are near overlapping need to get this much more in the center.

 

 

Screenshot 2019-01-15 at 23.13.01.png

How can I get that signal at the right point? 

Link to comment
Share on other sites

I just found a couple of pictures of a 3sgte distributor online and it looks like the sensors inside the distributor are all one piece so cant be moved in relation to each other.  I cant find any good close pictures of the two trigger wheels inside, can you confirm if the top (24teeth) and bottom wheel (1 tooth) can be moved relative to each other? 

Is trig 2 connected to the G1 or G2 sensor?  It might be a good idea to swap to the alternative one and then try a trigger scope to see if it is any better aligned.

Link to comment
Share on other sites

5 hours ago, Adamw said:

I just found a couple of pictures of a 3sgte distributor online and it looks like the sensors inside the distributor are all one piece so cant be moved in relation to each other.  I cant find any good close pictures of the two trigger wheels inside, can you confirm if the top (24teeth) and bottom wheel (1 tooth) can be moved relative to each other? 

Is trig 2 connected to the G1 or G2 sensor?  It might be a good idea to swap to the alternative one and then try a trigger scope to see if it is any better aligned.

The wheel it is a solid piece but it have a lot of teeth at the side and one at bottom.

I am afraid that I can't move them.

I have already order another distributor and we check in a couple of days again. 

Screenshot_20190117_112912.jpg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...