My 1976 TR6 is having trouble passing the AZ state emission test. Cruise
passes easily in both CO and HC. And idle CO passes pretty good. But it fails
the HC at idle. The state standard is 250. Mine started with a 485 reading.
After plugs, wires, and an AIR pump, and fixing the choke it was in the
380s. Then I installed the Pertronix, installed some chemical into the gas
tank
that helps you pass, and raised the idle, it is 303. It is still about 20%
from passing.
The emission station told me that it appears to be running too lean at
idle. So I wanted to set the timing to 4* after top dead center before I
adjusted the carb mixture. With the timing light on at about 800-1000 RPM idle
and
the vacuum connected to the dizzy, it is showing about 16* before top dead
center. When I turned the dizzy to get it to AFTER top dead center the idle
gets
much worse to the point where it dies even after raising the idle. I can get
it to run at top dead center, but when I give it some throttle, it backfires.
What is the proper method of checking/setting timing with the timing light?
4ATDC with the vacuum attached like I am doing?
On my 74 Ford Bronco, when I was having trouble passing emmissions at
idle, I ADVANCED it and it ran much cleaner. But I don't remember if it was
failing on CO or HC. So I am wondering if setting the timing to after top dead
center as opposed to before top dead center like it is now, if I will make it
flunk the emissions even worse. Any help and I will be much obliged.
Thanks.
Ken, AZ, 76TR6
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