Is there a way to increase off idle mixture on a Holley 780? Float lever is right at the hole, idle mixture screws in until it slows then backed out to high idle. Dies off idle until it gets good and toasty.
Which 3310, some are 780 some are 750 some have 1 metering block and some have 2 there are many. What engine is it on?Does it have enough timing? What is the list number?
Backed out ( do you mean screwed in ?) to high idle when warm is too lean 1/4-1/2 turn rich is better . what choke , manual , electric , manifold heat ? Curb idle , warm , on top step of cam ? For the record , " opening" or turning the adjustment screws ccw allows more idle emulsion into the idle circuit ( richening the circuit) " closing , or turning the screws cw allows less idle emulsion in to the idle circuit ( leaning the circuit)
If it is a daily driven rig and only has this issue in cold weather you might try running a stock type air cleaner with the provision foe a heat tube and rig up one of those flexible aluminum heat tube to the exhaust manifold/header. I had to take my chrome full flow air cleaner off and dig a stock one out of the shed and do that about 30 years ago. It looked like he'll but it ran at 10 below as soon as the exhaust started throwing off heat.
468 BBC, TH400, headers, no heat riser, open element air cleaner, manual choke. Happens summer or winter, always been like that. I do think it could use more accelerator pump, but it's fine once fully warmed up. I think I might try an electric choke. With the manual choke, if I give it enough choke to idle it loads up off idle. The automatic chokes open the up with increased airflow, I think.
Electric choke works off a heated bi-metal spring. It heats up and pulls the choke open. Nothing to do with airflow. I have asked why some engines are cold blooded and some are not on a couple of different forums. I have never got a good answer. I have a 355 that is cold blooded as hell. Aluminum heads and intake. No heat crossover passages. I have changed jets, idle feed restrictors, idle mix screw settings, electric choke settings and anything else I could think of to cure it. No luck. I have thought of putting a manual choke on it, but I haven't done that yet. What's really funny is I have a 383 that is set up just like the 355, aluminum heads and intake. Same carb. The 383 is not cold blooded at all. Starts right up, idles, and will take right off. Go figure
If it’s fine after warm up,,,,it’s not the carb . My 440 Tunnel Ram ,,(2-3310’s ),,was like that,,,,,,had to get to 100 degrees temp to be able to run well. After that it was fine,,,,,reached 180 fairly quick after that . Tommy
I'd have to go start up my Q-jetted 350 with a divorced choke, also bi-metal spring operated, but I'm pretty sure that as you rev it up the choke plate, being offset hinged, is pulled open by airflow against the spring pressure. Can't happen with a manual choke. Too early to go out and try it without pissing off the neighborhood. That engine, also no heat riser and open air filter, can be started and driven away moments later.
Guys, a carb is supposed to be cold blooded untill it is warm! That is what the choke is for. If it runs good cold, it is too rich! Holley didn’t put a choke on their carbs for shits and giggles! It’s there for a reason! Bones
What he said. The next important piece of information is: Every motor is different! The settings any one gives you is a starting point at which you adjust for that motor's best operation. And then, each carbureted motor has to be adjusted for the temperature range it is expected to operate in. If the outside temp changes 20 degrees, the motor may run OK, but its not running its best. A 40 degree change can completely change how a motor runs. That was one reason motors were tuned every spring and every fall, to adjust for the upcoming season's driving outdoor temps.
Question I should asked right from the beginning? What intake? Is it exhaust heated? Do you heat the intake air like a stock engine?
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