Timing issues - Advance questions

[SadbutTrue]

Yeah, my car still pings (it has the below done to the engine, which is basically nothing, and with a 9.5 compression ratio it pings with 91 at times, with 87 pretty much always... it should run fine on 87). This is with my carb rejetted to run on the richest setting the adjustment kit will allow (also a reason for fixing, the richness has caused my mileage to dip into the 8 mpg zone).

I think its still the advance, because the intial timing is only about 8 degrees. I don't have anything to measure total timing, but because the pinging only occurs at mid to high rpms and I can "throttle my way through" the pinging (ie it will ping from say... 50-85% throttle and after that it will stop), I believe its the advance.

I was told that the mechanical (inside the distributor) portion of the advance (I'm using a stock Ford vacuum advance) has some parts that can rather easily and often come apart and cause problems like this... can anyone reiterate what these parts are and how to identify and fix the problem? Also, I don't know if my vacuum advance does, but I've been told that at least some aftermarket ones have tiny screws in the vacuum port that can be adjusted to fix vacuum related issues. Can anyone also tell me the procedure with that?

Thanks a ton.

 

[thehueypilot]

Is your engine running on the hot side temp wise? Maybe cooler range spark plugs would help. Maybe your engine has a lot of carbon build up in it? One trick to loosen carbon build up is to pour a small amount of transmission fluid in the engine while it is running to loosen up the carbon, but use a little bit and yes it will smoke like hell. Is your vacuum advance seeing any vacuum at idle? It should not see any.

 

[10secgoal]

Did you use a stiffer spring ? If you do that, the enrichment circuit will come on sooner, and you can jet the carb back down for normanl driving. It sounds like it is only doing it under a load. The timing of the richer state may be the problem. If you can pedal through it, all your doing is giving it a pump shot to cover the lean spot in the rpm until the spring pulls the rod out of the jet.

 

[brianj5600]

Try unplugging the vacuum going to the distributer. Sounds like too much vacuum advance to me. I think crane sells adjustable ones, try their site for instrctions.

 

[pabear89]

Well, The internal springs do sometimes break on the counterweights.
but it seems your having the problem of too much advance too soon.

If you have a Vac pump that you can draw on the Dist advance with,
Check to see how much vac it takes to move the breakerplate,
and how much it takes to move to full advance.

The screw in the Adv pot has a spring controlling the amount of vac needed.
turning it Counterclockwise will lenghten the spring requiring more Vac to operate.

Without a Adjustable timing light and Vac pump,
you have to do the trail and error method.

PB

 

[SadbutTrue]

isn't there some sort of rubber peice that can come off off the mechanical parts under the plate that holds the points (on one with points, since mine has a pertronix)