69 Toronado Quadrajet Secondaries Not Opening

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NicolasB
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Re: 69 Toronado Quadrajet Secondaries Not Opening

Postby NicolasB » Sun Oct 04, 2020 5:36 pm

So I finally bought a vacuum gauge and tried to tune the carb myself to get rid of the smoke, but it’s still there when I press the pedal. It eventually goes away after doing WOT more than four times, but I don’t think that’s normal. I tuned it to the (best) max vacuum for both mixture screws. I saw the spark plugs and noticed that they’re filled with soot and are black. Guessing it’s a rich mixture. But what else can I do to fix this?

bcroe
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69 Toronado Quadrajet Secondaries Not Opening

Postby bcroe » Sun Oct 04, 2020 7:00 pm

Something needed for EFI, but also useful on a carb, is a Wide Band Oxygen Sensor.
These have become quite affordable, such as Evil bay 402284370664

APSX V2 Anti-Glare D2 Digital Wideband O2 AFR Gauge & Sensor Kit

I have been running a couple of them on EFI and carb engines for many years, to
see exactly how much it is rich or lean. Get one with moving scale, that digital
readout will just be a blur of segments on a transition, just when you need it.
Bruce Roe
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Otto Skorzeny
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Re: 69 Toronado Quadrajet Secondaries Not Opening

Postby Otto Skorzeny » Mon Oct 05, 2020 1:55 pm

Hi Bruce,

On the Quadrajet, do the mixture screws affect the fuel air ratio throughout all circuits or just the idle mixture?

bcroe
Posts: 248
Joined: Thu Nov 15, 2012 12:25 pm
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Years Owned: 79 Toronado or Eldorado

Re: 69 Toronado Quadrajet Secondaries Not Opening

Postby bcroe » Mon Oct 05, 2020 3:15 pm

My understanding is the jets control mixture for driving, the mixture screws primarily for
idle, the air for idle by that throttle idle screw. On EFI it is the injector pulse width vs
Manifold Absolute pressure. Temp, altitude, rpm, transitions, etc will have some effect.
Bruce

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Otto Skorzeny
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Re: 69 Toronado Quadrajet Secondaries Not Opening

Postby Otto Skorzeny » Mon Oct 05, 2020 5:57 pm

Thanks Bruce.

NicolasB
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Re: 69 Toronado Quadrajet Secondaries Not Opening

Postby NicolasB » Sun Oct 18, 2020 1:06 am

This might not be the reason why (and I haven’t tried it yet), but is the way that I turn on my Toro a cause for soot to leave in the exhaust? I heard that you usually press the accelerator all the way down, let go, then try to turn the car on. This apparently activates the high idle cam. I usually press it all the way down, but put a bit of gas and hold it when I crank it. Could this cause the rough start to happen (probably cause the idle to drop)? Or would I still need to adjust the choke (it’s completely closed)?

Update: I replaced the old spark plugs with new AC Delco copper plugs and the car feels better already. Still did not do much with the smoking issue. I also had to readjust the carb because it was bucking when I pressed the throttle (possibly made it too lean). I made the mixture richer and it doesn’t jerk anymore, but there’s a slight (but smooth) delay when I press the accelerator (like half a second).

NicolasB
Posts: 63
Joined: Sat Apr 25, 2020 9:27 pm
TOA Membership Number: 0
Years Owned: 1969 Oldsmobile Toronado

Re: 69 Toronado Quadrajet Secondaries Not Opening

Postby NicolasB » Sun Oct 18, 2020 1:09 am

NicolasB wrote:This might not be the reason why (and I haven’t tried it yet), but is the way that I turn on my Toro a cause for soot to leave in the exhaust? I heard that you usually press the accelerator all the way down, let go, then try to turn the car on. This apparently activates the high idle cam. I usually press it all the way down, but put a bit of gas and hold it when I crank it. Could this cause the rough start to happen (probably cause the idle to drop)? Or would I still need to adjust the choke (it’s completely closed)?

Update: I replaced the old spark plugs with new AC Delco copper plugs and the car feels better already. Still did not do much with the smoking issue. I also had to readjust the carb because it was bucking when I pressed the throttle (possibly made it too lean). I made the mixture richer and it doesn’t jerk anymore, but there’s a slight (but smooth) delay when I press the accelerator (like half a second).


For the first part, I’m referring to a cold start.


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