Pinging?

[mentalQtip]

Happy weekend, guys.
My '77 f.i. bus has been progressively making a sound that I can only think of as pining. It really needs rings alot and puts out a bit of blue smoke but it passed DEQ a couple of months back.
I was wondering about the pinging(?) getting worse and what would cause the change.
It happens when I give it more gas.
Could it be running real lean and that is why it passed DEQ? But why didn't it ping earlier?

An inquiring mind wants to know.

Thanks

Joseph

[supaninja]

Carbon build up could cause it. One thing you can try is running some Seafoam through the motor, it's called "de-carbing". That stuff works miracles.

[Jadewombat]

Try running a higher grade gasoline through it than what you have been to see if the noise goes away. I.e. if you run 87 octane then try 89.