Ron---As Steve wrote, when the retard system is operating correctly,
the idle speed should drop several hundred rpm when the retard line is
connected.
10 deg. BTDC is a good place to start when settting the timing with the
vacuum DISconnected and plugged. The idle speed will be higher then, but
should return to "normal" when you reconnect the vacuum line.
Do not set the timing to 4ATDC with the line disconnected, as this is
not an engine efficient timing setting. Again, set it to 12BTDC and
reconnect the vacuum. If this reconnection doesn't drop the idle or
retard the timing, further investigation is necessary to determine why.
The temperature switch vacuum interrupter has no influence on the
timing, until a very high coolant temperature is reached (about 200). At
this point the retard action will be canceled, and idle speed and timing
will advance.
Finally, check the oil in the carburetor dampers. Low/no oil will also
cause the hesitation that you are experiencing.
Dick
Ron wrote:
My 72 TR6 is running a little rough and has a hesitation when
accelerating from idle. I was doing my normal tune up for my emission
testing and things seem to be going from not too bad to worse. I believe
the vacuum advance is not working properly. When I remove the vacuum
line from the distributor there isn't much change in the timing.
I removed the line before adjusting the timing and think I remember a
big change in the timing. I adjusted the timing to 4 degrees ATDC as I
always do. When I plugged in the line the timing didn't seem to change
much. I don't know if the hesitation is with the vacuum advance or some
other type of problem.
The distributor cap, rotor and points (checked gap) look ok. The lugs
inside the distributor cap look as if they are aluminum. Shouldn't these
be copper? If so does anyone know has this type.
I appreciate any suggestions anyone out there might have.
Thanks,
Ron Olds
72 TR6
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