dumb timing question (1 Viewer)

[fyton2v]

My engine sputters when I turn off the ignition. Using my oh so limited knowledge on engines I figure it's probably a timing issue and since I don't own a timing light I have now given myself an excuse to buy one. So off to Sears I go and I get a light with an advance dial.

Tell me if I'm reading this correctly. The silver ball is quite a bit lower than the needle... this is "advance"... at least this is what I’ve learned after liberal use of the search feature on this site. When I turn up the advance knob the ball will rest on the needle at 7. So this is 14 degrees of advance?

Can I assume that this is a true reading?

In general, what causes sputtering? Too much advance or not enough?

As usual... Thanks man.

 

[TonkaC]

a lot of the time it is a high idle that will cause the desieling (running backwards once shut off). It could also be the little plunger that gets twelve volts that is mounted on the carb. I can't remember the name of it, but it is the only thing on the carb that gets 12V.

 

[coiled40gary]

AS far as I know, there are a lot of things that can cause run on, too much advance, too lean, carbon build up... There are a lot of people here that know what I would be guessing at. But your dial back timing light...
You are right, the bb is the factory setting of 7 degrees advanced when lined up with the needle. So if your light is set on 0 and the bb is lined up, you have 7 degrees. With the it lined up and 7 degrees on the light, you have 14 degrees advance. I set mine at 15 degrees advanced at 600 rpms. If you have the bb lined up with the dial set on 7, turn the dial to 14, and you will see a horizontal line on the flywheel line up with the needle. This line is TDC. If you use the line instead of the bb, you can read the dial settings directly. Getting a dial back timing light was a good choice. You can check the functioning of your advance mechanisms, you can plot your advance curve, as well as accurately set your timing with the little feed back Toyota provided us. If your engine is modified, you will probably want to play around with other than factory settings, and your timing light will allow you to do that with more repeatability than "well, I just made the bb disappear from the window".

gary

 

[elblat]

Low octane gas will also cause running-on or dieseling, but usually only on higher-compression engines.

I run my timing about where it sounds like yours is and don't have a problem, it could be the idle cut-off solenoid.