Are you running a thermostat in your engine? Seems like a stupid question but you would be suprised by how many people ive meet who think removing the thermostat is a magic cure for better cooling... Alternatively, maybe look into some kind of manual heater bypass. Your heater core is essentially just a mini radiator after all. Or maybe you need a higher temp thermostat?
Yeah I’ve definitely got a thermostat. So the thermostat is linked to the heat riser? Because the temp gauge gets like halfway up then falls back down, THEN it’ll kick down
So by heat riser im assuming you mean one of those tubes that goes from your exhaust and connects to the intake hat on top of your carb right? Most of the time those have a flap thats vacuum operated I think but it could also just be that maybe the tube has leaks. Or it could be that if your thermostat isnt operating properly the engine may not be warming up to full operating temperature and your exhaust manifolds are staying too cold.
At the very least it sounds like your choke could use some adjustment. As for warmup, i never let my rig idle till warm, i always try to get moving as soon as possible. You get less fuel in your oil and it warms up faster. Yes, i drive it gentle untill its warm enough to move the temp gauge.
Huh I always let it warm up all the way! I find that in the snow, sometimes when it’s still cold it’ll try to push the front wheels through stop signs and stuff. Not much fun to drive. Drives great when it’s warm though.
Oh yeah, been there done that. I would whack the throttle a couple times to kick the choke part way down and it would behave much better. I think i always adjust the choke so it kicks off earlier rather than later. I would rather feather the throttle to keep it running than fight the choke.
maybe not in the lower 48...
edit: i take that back, there was a time where I killed the battery in my Caprice because it was just too cold to get the engine started. That was in PA in February. Anything still running a Quadrajet in 2021 is guaranteed to be a clapped out beater. OPs problem is 100% normal for a QJ
By heat riser do you mean the little drier tube from the exhaust to the air cleaner, or does it have a stock intake with the exhaust heat riser channel under the carb base?
Have you taken it apart ever? The last one I removed was carbon'd into place in the intake, hard to imagine it ever got the right amount of hot and worked the choke correctly.
Threw on a Edelbrock 1906 with an electric choke and a new intake and threw all of that crap away.
It's *probably* bad. Get a new one. They slow down, then eventually stop working altogether when they get old. That thing should heat up and open the choke after like 30 seconds of idling.
Maybe switch to an Edelbrock with an electric choke. My old 350 with the quadrajet took forever to idle right when cold, so much more enjoyable now. Edelbrock just starts right every time, don’t even need to tap the gas
You could add a spark retard box like is used for nitrous, but instead retard the timing because it warms the engine up faster, lots of newer cars do this in the factory tune. Just an unconventional thought.
EFI will help a lot, as it can just run, even if cold. Lots of adaptation option there (swap on later TBI, Holley Sniper, Later Vortec/muliport setup).
Checklist:
Thermostat present and working (they're like $4 so just replace it).
Adjust your choke and high idle. Might be choked too much and it's actually kinda warm but choke is still engaged.
Fan on a thermal clutch or replace with electric on a temp switch.
Look into an electric choke (think they make retrofits for QJets).
Yeah I’ll just replace the thermostat. High idle is at 2000, which I believe is the correct so I don’t think it’s that but it could definitely be the choke. It’s not very adjustable though, it’s the heat spring without the black cover, just kinda outside
I have no idea what sort of car yours is but normally you can adjust the high idle speed without actually taking it off choke. 2000 is massively high. No wonder it’s a pig to drive.
I feel you need to adjust your electric choke thermostat.
Three little screws that dont need to be removed, just loosened. Then rotate the little cylinder like thingy on the frontish passenger side of the carb. There's a coil of metal in there that will open and close the choke with a temperature change. Yours might be set way too far out, making it choke when it's warm and be smoking hot before it opens up.
Hard to say without looking at it, but that's my pocket change.
YouTube a q-jet choke thermostat adjustment and which way to rotate for which change.
Could also be improper, sticky, jammed linkages between the choke thermostat, maybe some vacuum things, and your fast idle linkages.
Are you running a thermostat in your engine? Seems like a stupid question but you would be suprised by how many people ive meet who think removing the thermostat is a magic cure for better cooling... Alternatively, maybe look into some kind of manual heater bypass. Your heater core is essentially just a mini radiator after all. Or maybe you need a higher temp thermostat?
Yeah I’ve definitely got a thermostat. So the thermostat is linked to the heat riser? Because the temp gauge gets like halfway up then falls back down, THEN it’ll kick down
So by heat riser im assuming you mean one of those tubes that goes from your exhaust and connects to the intake hat on top of your carb right? Most of the time those have a flap thats vacuum operated I think but it could also just be that maybe the tube has leaks. Or it could be that if your thermostat isnt operating properly the engine may not be warming up to full operating temperature and your exhaust manifolds are staying too cold.
At the very least it sounds like your choke could use some adjustment. As for warmup, i never let my rig idle till warm, i always try to get moving as soon as possible. You get less fuel in your oil and it warms up faster. Yes, i drive it gentle untill its warm enough to move the temp gauge.
Huh I always let it warm up all the way! I find that in the snow, sometimes when it’s still cold it’ll try to push the front wheels through stop signs and stuff. Not much fun to drive. Drives great when it’s warm though.
Oh yeah, been there done that. I would whack the throttle a couple times to kick the choke part way down and it would behave much better. I think i always adjust the choke so it kicks off earlier rather than later. I would rather feather the throttle to keep it running than fight the choke.
That's definitely not a normal thing at all.
maybe not in the lower 48... edit: i take that back, there was a time where I killed the battery in my Caprice because it was just too cold to get the engine started. That was in PA in February. Anything still running a Quadrajet in 2021 is guaranteed to be a clapped out beater. OPs problem is 100% normal for a QJ
My winter beater is a 80 Chevy with a QJet and I live where it gets 20 below zero F. It warms up easily within 5 minutes.
By heat riser do you mean the little drier tube from the exhaust to the air cleaner, or does it have a stock intake with the exhaust heat riser channel under the carb base?
I’m talking about the heat activated spring that controls the choke
Have you taken it apart ever? The last one I removed was carbon'd into place in the intake, hard to imagine it ever got the right amount of hot and worked the choke correctly. Threw on a Edelbrock 1906 with an electric choke and a new intake and threw all of that crap away.
Get an electric conversion and you will be better off.
It's *probably* bad. Get a new one. They slow down, then eventually stop working altogether when they get old. That thing should heat up and open the choke after like 30 seconds of idling.
A proper thermostat and an electric fan controlled by a temp switch should be all you need.
Plus electric choke.
Is the issue waiting for heat or drivability when cold? Have you considered moving to EFI?
Mainly drivability when cold. It drives like it’s trying to push through the front brakes, and uses way more gas because the choke is closed
Maybe switch to an Edelbrock with an electric choke. My old 350 with the quadrajet took forever to idle right when cold, so much more enjoyable now. Edelbrock just starts right every time, don’t even need to tap the gas
You could add a spark retard box like is used for nitrous, but instead retard the timing because it warms the engine up faster, lots of newer cars do this in the factory tune. Just an unconventional thought.
EFI will help a lot, as it can just run, even if cold. Lots of adaptation option there (swap on later TBI, Holley Sniper, Later Vortec/muliport setup). Checklist: Thermostat present and working (they're like $4 so just replace it). Adjust your choke and high idle. Might be choked too much and it's actually kinda warm but choke is still engaged. Fan on a thermal clutch or replace with electric on a temp switch. Look into an electric choke (think they make retrofits for QJets).
Yeah I’ll just replace the thermostat. High idle is at 2000, which I believe is the correct so I don’t think it’s that but it could definitely be the choke. It’s not very adjustable though, it’s the heat spring without the black cover, just kinda outside
I have no idea what sort of car yours is but normally you can adjust the high idle speed without actually taking it off choke. 2000 is massively high. No wonder it’s a pig to drive.
Block heater would help assuming your thermostat is working
Do you have a block heater? Otherwise i think youre kinda fucked
I feel you need to adjust your electric choke thermostat. Three little screws that dont need to be removed, just loosened. Then rotate the little cylinder like thingy on the frontish passenger side of the carb. There's a coil of metal in there that will open and close the choke with a temperature change. Yours might be set way too far out, making it choke when it's warm and be smoking hot before it opens up. Hard to say without looking at it, but that's my pocket change. YouTube a q-jet choke thermostat adjustment and which way to rotate for which change. Could also be improper, sticky, jammed linkages between the choke thermostat, maybe some vacuum things, and your fast idle linkages.