Gurus; How do I get my Qjet to come off the choke a little quicker in the cold?
On my 327 when I rebuilt it, I did the partial restriction of the heat riser passage at the intake gasket, and I used a gutted heat riser as well. Even when I see 180 on the gauge, she still stays on high idle when out on the road, until I imagine that the spring heats up enough to keep the choke valve fully open. It will come off with a throttle blip, but then comes back on again at moderate throttle and stays a little bit too long.
Just would like it to come off fully just a little quicker.
Any ideas of what to adjust?
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65 Laurentian post, 67 Grande Parisienne 4 door HT.
Hi Mark I talked to my friend Jim who is a retired old style GM performance mechanic and very knowledgeable, he says your problem lies with the heat riser. If it is gutted it isn't allowing enough heat to kick the choke off completely. Recommend replacing the heat riser with a new one available with Four Seasons brand My 50 cents worth (inflation). ARCADIAN Chris
-- Edited by ARCADIAN on Monday 11th of January 2021 12:31:44 PM
I'd adjust the length of the rod from the choke thermostat on the intake to the carb. If it's like my Q-jets, lengthen the rod so it takes less heat to pull the choke off.
Thanks Guys, I'll have a look today. Probably start with the rod height and make sure the weight is free. I don't think I'll install a actual working heat riser, as the car will be mostly warmer weather driven. I suspect it's simply that the spring takes too long to heat as the issue.
Here's a neat 67 vintage Rochester division film on the basic function of a Qjet choke, highlighting the correct starting sequence. Doesn't describe adjustment, but is still pretty interesting. Shows a BB as well.
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65 Laurentian post, 67 Grande Parisienne 4 door HT.
On my 1970 quadrajets, the choke thermostat pushes the rod up as it heats up. I know the 70 2 bbl the choke thermostat pulled the rod down as it heated up.