i have a 69 camaro 305 built engine that i am having problems with. i can set the timing but when reving up the engine the timing does not change any. vaccum advance also does not change anything. the car runs strong when timing set at 30btc at 2500rpm but is hard to start when hot. if i lower timing starts ok but runs poor. what do look i look for. why does the timing not change.
if i set it at 2500 rpm then drop back to 1000rpm there is no change. i can run it up to 3500 rpm and still no chang. any ideas.

The centrifugal advance mechanism is stuck (weights/springs under the rotor); remove the pieces, clean, and re-assemble with a drop of lube on the pivot pins.

Either that or the springs are broken or missing.

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JohnZ
CRG
'69 Z28 Fathom Green

thanks i will look at that in the morning

i have the cap & rotor off and the weights move freely and springs are in place.
should i be able to move advance mech. by hand? weights fit very loose on pin, is this correct? thanks

You should also be able to grab the plate under the weights and turn it about 20 degrees by hand, and it should snap back by itself - if it doesn't, the autocam mechanism is frozen up.

Or, the springs could be so weak that you're getting full advance all the time, even at idle.

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JohnZ
CRG
'69 Z28 Fathom Green

the center plate under with the springs would not turn at all. i was able to get the center plate off, but it fits down on the teeth of the shaft. is this correct? should it fit this far down. how does it turn. i cleaned and oiled but did not correct anything. the bushing in the center plate looks like someone had maybe driven it down on the teeth of the shaft. should i buy new center plate and try that