When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I was fixing the carb. dashpot on my 1971 Cutlass w/ 350 4 bbl. I assume these cars had no solenoid or other device to increase idle speed when the A/C compressor was engaged. Correct??
It started life on my 71 442 BBO motor but when the Fi Tech throttle body fuel injection was added, I didn't need it anymore so I added it to my 70 Supreme SBO motor. I have a toggle switch under the dash that activates the solenoid. So my cars both drop the RPM about 300ish at idle at a stop light when I turn the AC on. I like my idle around 850ish. So if I turn the AC on w/o the solenoid the car drops to about 550 RPM and either stalls or gets close to stalling unless I press on the gas pedal. Some folks just crank their idle up to around 1150 and then they are covered AC or not but I can't stand my car to idle that high. This is where the solenoid comes in.
While in Park my car idles around 1150. You should only activate the solenoid while in Park. For the AC I flip the toggle forward and step on the gas and that little gold part you see on the solenoid in the pic extends out and adds 300 RPM (after I dialed it in perfectly). So while in Park still the idle goes up from 1150 to 1450. Then I turn the AC on and it idles perfectly around 1150 (yes all 300s for me!) while still in park and around 850 RPM in drive or reverse. When I turn the AC off I just turn it off first, then click the toggle the other way (again in Park) and touch the gas pedal and everything is back to normal. Sounds like a lot as I write all this out but it's really pretty easy. I can do it while in Drive too but you just have to be a little careful since the solenoid only activates or deactivates when you touch the gas.
There are also some other added benefits to the solenoid toggle. I use it in the winter for longer warm ups as a choke alternative and other random times. You have this additional 300 RPM at idle you can activate at any time. I will say the throttle body fuel injection that does the RPM increase on it's own is one of the many benefits to that upgrade but if you're running a carb and AC this is a nice option to have and for less then $100 for the part and a little custom bracket work to get it in the right location for your carb, you could get everything done in a day.
My car is almost 100% original. Just verifying there's no A/C gadgets. You could wire it to the clutch wire I'd guess. I was wondering if there was something from a later Olds carb car available.
Confirming whether or not there were A/C solenoids in your year is able to be done by checking the CSM under tune-up. Either it mentions it or it does not. I do not recall there being one this year. What there was was an idle control solenoid, like shown here. This took 12 VDC off a jumper leading to the TCS tree and was energized when ignition on. The idea was that you stood on this solenoid for slow idle, and, when shutting off, you went to the slow idle screw, which was set at a barely sustainable idle. This help avoid dieseling.
Since your car has a dashpot, you could remove, install one of these, hook to AC clutch wire or something similar purpose, and it would engage with the compressor. You would lose the functionality of the dashpot, which is a buffer to not allow idle to dip too low when you let off. However, you could tune slow idle to help with that if it is a problem.
But, the short answer is no, these years did not, and they were idle adjusted to a spec with AC off that could tolerate the drop of AC being on.
Correct, stock these cars just had the dashpot which slows throttle closing when you abruptly take your foot off the gas. Later years had the fast idle solenoid.
The '72 (and maybe '71??) Qjets had the mounting posts for the fast idle solenoid in the casting. Earlier ones do not. So you need a '72 (maaaaybe '71?) or later carb, bracket, solenoid, nut, and nut retention ... uh.. thingy. When I went looking some years ago the bracket was the hardest part to find. You may or may not have to do some creative engineering to get the nose of the solenoid to hit the throttle bracket correctly. Seems they designed the feature for '72, but it didn't make it into production until '73.
The solenoid you listed is **not** correct for the Olds style qjet. That actuation arm is waaay too long.
It should fit. This is what my current dashpot looks like (photo not mine). My bracket is mounted in holes cast in the intake. For 30.00 I'll give it a try.
Correct, stock these cars just had the dashpot which slows throttle closing when you abruptly take your foot off the gas. Later years had the fast idle solenoid.
The '72 (and maybe '71??) Qjets had the mounting posts for the fast idle solenoid in the casting. Earlier ones do not. So you need a '72 (maaaaybe '71?) or later carb, bracket, solenoid, nut, and nut retention ... uh.. thingy. When I went looking some years ago the bracket was the hardest part to find. You may or may not have to do some creative engineering to get the nose of the solenoid to hit the throttle bracket correctly. Seems they designed the feature for '72, but it didn't make it into production until '73.
The solenoid you listed is **not** correct for the Olds style qjet. That actuation arm is waaay too long.
I'm not quickly finding a bracket for sale. It's large, mostly flat, bolts to the *front* of the qjet, like shown in Koda's picture.
They existed in 72 and bolted right up to the quadrajet. The hardest thing, indeed, is to find the bracket. My bracket and nut came from one guy, my screws from another, and the NOS solenoid came from a third.
To wire this thing, there is a jumper harness for the TCS tree's power that jumps the 12 VDC off to this. The ground from the transmission is passed through. My car had it gone, but still had the 12VDC wire in the harness, so I spliced a lead onto it. If it fails on the road, I can crank up the idle screw to get home.
Ah, if you want to bolt something in place of the dashpot, yeah, that one might work with the dashpot bracket. That long nose might actually be too short, so you might need to add something to the end of the actuator. Or not.
Ah, if you want to bolt something in place of the dashpot, yeah, that one might work with the dashpot bracket. That long nose might actually be too short, so you might need to add something to the end of the actuator. Or not.
That's my thought at this point. I'll see once the part is received. I plan to run a wire from the clutch side of my temperature switch on the evaporator to this solenoid. Then it should engage w/ the clutch.
That's my thought at this point. I'll see once the part is received. I plan to run a wire from the clutch side of my temperature switch on the evaporator to this solenoid. Then it should engage w/ the clutch.
May want to be off idle, or blip it, after engaging. These solenoids can't push the throttle up, they just hold it up once they are allowed to extend. On an idle solenoid car, if it can be started with no throttle warm, it will be on the slow idle screw till blipped once, then the solenoid can extend itself and it will be on it. I restarted my 72 during garage work by reaching in and turning the key. It started bubbling away at 500 rpm in park. Grab the throttle linkage, one hit, and now we're at a much nicer 1000 in park.
May want to be off idle, or blip it, after engaging. These solenoids can't push the throttle up, they just hold it up once they are allowed to extend. On an idle solenoid car, if it can be started with no throttle warm, it will be on the slow idle screw till blipped once, then the solenoid can extend itself and it will be on it. I restarted my 72 during garage work by reaching in and turning the key. It started bubbling away at 500 rpm in park. Grab the throttle linkage, one hit, and now we're at a much nicer 1000 in park.
John is right on this, I put a factory type solenoid on mine when I got A/C working and it won't push out to increase idle, but will hold it up if throttle is coming back down. Works good as long as you know that.
I have the bracket adjusted & ready to run the wire to the clutch circuit. I just wondered whether this is a constant duty solenoid. It will have constant power when energized. I assume this is OK of course. Correct? It won't burn out? Here is a rough fitting. I still need to attach it solidly & fine adjust the speed when it gets warmer & I can run the A/C compressor.
