Olds 455 this time, with a quadrajet. When it gets into the 30s, I step on the throttle once to close the choke and set the high idle. Engine will run for one second, then die. Cranking it a second time it will run for about three seconds, then die. The third time it will typically stay running. It is VERY consistent. When stepping on the gas (once), the choke snaps fully close and the high idle cam raises the idle. I even put fuel in the fuel bowl to make sure I don't have a dry bowl. Same thing. Also tried raising the fast idle (I estimate it's at about 1200 RPM now, in Park). Any suggestions? Thanks. For reference:
Where are you located? In those temps (assuming we're talking Fahrenheit) a single pump of the gas pedal may not be sufficient, especially if the carb's accelerator pump seal is suffering due to ethanol in today's North American gasoline. Try two pumps of the pedal, maybe it'll need three. If that doesn't do it, time for some more troubleshooting. Don't want to flood it. Or are we talking Celsius? That would be on the other end of the spectrum! Devon
Most likely needs a couple extra pumps of the pedal, taking into account (as Devon mentioned) today's lousy fuel. The caveat is: we only have basically one chance a day troubleshoot choke issues. That's the catch. Ask me how I know....
Another thing, if you're in the USA (not sure about Canada) we switched to winter blended fuel recently. If you have a tank full of summer fuel, it won't vaporize easily in cold temps, so some fresh gasoline from the current seasonal blend may help too. Devon
Check the front vacuum break. Besides controlling the rear secondary air flaps, it ALSO opens the choke against thermostatic spring tension. That allows the engine to run without loading up. I just installed an electric choke from Ken at Everyday Performance. I made a video using my remote start. Watch the vacuum break react as soon as the engine starts, and it opens the choke flap enough for the engine to run at fast idle. If the vacuum break is bad, the engine will choke out as soon as it starts.
In cold enough weather, you can reduce the amount that the choke pull-off opens the choke plate. Might take a couple of tries. This would mean increasing the pull again, come warm weather. This was a common thing in era of these cars.
I would check the choke pull off. There is a spec it should open when it fires. It needs to be just right. Its vital to proper choke operation
Besides the crap fuel and summer/winter blends, back in the day there were many different choke pull-off opening rates for different applications. Now aftermarket companies have consolidated and many times they open too quickly and cause a stall.
So this morning I tried three pumps and it went from the usual three starts before a steady idle, to two, so certainly an improvement. Unfortunately I won't be near the car until next weekend. I will try the other suggestions. Thank you.
