Im running 93 octane and have 9.6:1 compression.

What should my base timing be without the vac advance hooked up? How about with it hood up.

I checked today and it looks like im right around 35 degrees total but at like 5 degrees base.

I think I may have a bad vac advance because I set the base timing without the vac lines plugged to 5 degrees then it used to jump up with the lines attached.

I dont know Im fighting a random dieseling problem. Every now and then it will diesel. Its either my timing, my carb (way to much gas), or my rpms (not likely)

 

Unless you have a really short duration cam that is trapping a lot of compression in the chambers, you should be able to get away with more initial advance than 5°. A stock TPI has about 9.5:1 compression and runs 6° initial advance on 89 octane fuel. Most times that can be increased to 8-10° or more without creating issues on 91 octane, so 93 should be able to tolerate a bit more. Then again, every engine and engine build is slightly different, so you'll have to experiment.

As for total advance, a vacuum pump and timing light will help determine what yout vacuum advance unit is doing. Many engines with a working knock sensor can take 46° total advance without problems, while factory ECM programming often sets the total advance at 41-42°.

 

i run my 305 carbed at 8º to 10º pass 0º and its 9.5:1 and i only run 93 pump gas.

 

I have no knock sensor so I cant go by that.

So try setting the timing to ~8 degrees with the vaccum advance hooked up or without?

 

with....always with