Im trying to time my 82 305 (carbed)but I dont know how to read the teeth. There is 4 teeth on the little tab and I dont know what they mark.Which on eis 0%.

Also when I start the car it idles at about 2000 until is runs for a second then you rev it and it drops back down to about 600.My brother says it sounds like a choke issue. What do you think?

And finally when it has run for a while after you turn it off about 5 seconds later there is a loud pop. Like one back fire or one deisel combustion. I think its a timing thing but Im not sure.


Any help would be appreciated. Thanks.

 

The high idle on start-up is a normal condition. It is the cold start idle. If you punch it and the idle goes down it is working properly. The 0 deg mark on the tab is on the right side of the tab when standing in front of the motor. The 0 deg is a slightly wider 'V'. If I'm wrong will someone please correct me.

 

It's hard to correct someone when they are right, so I'll just add a little.

The large 'V' is TDC, or 0°. The smaller 'V' notches are in 2° increments. If you clean off the timing tab, you should also be able to see the individual lines that are in 1° increments. Stock tabs usually have one notch below the Zero mark (ATDC) and 3-4 notches above the Zero mark (BTDC).

 

Todd is right on both counts. Advance is toward the pass side of the motor.

The pop is unburned fuel that has been drawn through the motor while it spins down after the ignition is off, igniting in the cat. Nothing to worry about. Certainly not something you fix with "timing". Lower idle speed maybe but not timing.

 

There is a pic of a timing tab in this thread, may be of help:

https://www.thirdgen.org/techbb2/sho...ng+AND+picture

It is from an '85 305 4bbl motor.

RBob.

 

Thanks for all the help guys.