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automatic choke woes

I was asking others if they thought removing them and blowing the "passage" out with compressed air might help.

I don't particularly see how it could hurt. As already mentioned, pull them all the way out (don't lose the springs) on reinstall in all the way until seated, and then back out 2-2.5 turns, fine tune from there.
 
Okay. I think that's what I will try as soon as I get a chance. I've been so busy this month so far it's ridiculous.
 
A little bit of a different beast, but edelbrock instructs you to put compressed air through the passages to clear them out.
 
yes, you can use air. preferably as a follow up to carb cleaner on bogs...
 
..

I tried blowing compressed air into the ilde mixture screw on a Tecumseh carb awhile ago on a snowblower,hoping to blow out any crap blocking the passages,it was not making any difference where I set the adjustment..

After I put the mixture screw back in and started it up,it now flooded like crazy,gas was pouring out of the air cleaner like a faucet!..

Took the bowl off ,and found the float was smashed flat,like I had stomped on it!.:eek1:..guess it didn't like that!..I wont be doing that again soon,it was 12 bucks for a new float,and as much for the gas to go find one too..:doah:

I dont recall any other car or truck carbs doing that ,but then I have not tried blowing compressed air into their idle jet holes that I can recall either..
 
The Tecumseh carb body does have a vent,two styles--either on one side of it,its about a 1/64" sized hole though (thats what the carb I was fixing had)--some others had an internal "nozzle" vent that is located near the choke plate,those are a bit larger ,and probably would not allow enough air pressure to build up in the bowl to make the float implode like that!..

I had another lawn mower carb float blow up like a firecraker once--it had a pinhole in it and I poked it open a bit bigger to let the gas inside escape before I attempted to fix it by soldering it...not having a hot sunny day at hand to let it evaporate outside in the sun,I decided to lay it on my wood stove,which was fairly hot--about a minute later,it went off like a little brass bomb,and shrapnel flew past my face!..:eek:..so much for fixing that one!..:doah:
 
Can't hurt to try, might blow some fuel out of the float bowl thru the jets but won't hurt a thing. More than likely one of the idle tubes is restricted and will req disasembly.

If you do open the carb up get a good kit that will hold up to ethanol.

I get my kits from cliffshiperformance.com , they also have a quadrajet forum. I don't use over the counter kits.

Make sure the choke pull off works also, it opens the choke just about 3/16 on start up but I think you said even when warmed up it idles bad with the choke open all the way that leads back to dirty idle passages. Once the the choke is open and engine warmed up the choke is out of the loop.

Make sure you have no vac leaks first off, that will throw everything off.
 
I'll check them out. I have had to run crappy gas with lots of ethanol plenty of times. It's hard to find a Chevron or BP around here. (Plus I have to stop for gas every 150 miles, so sometimes I can't be too selective). :rolleyes:

When I had the air filter housing off, I covered the intake port thing with a rag for a second and it acted like it was going to stall if I left it on there. That means no vacuum leaks right? I always thought that if there was a vacuum leak, the engine would keep running if you did that.
 
Hahahaha. Nope. It's got a 16 gallon fuel tank and it gets 10 mpg, so I could technically go 160 miles, but I don't like to risk it. :D
 
No not really, if u cover the opening completely it's going to stall.
Spray carb cleaner or brake cleaner around the base of the carb and vac lines etc without getting it in the opening and the rpm will change if you have a leak. Spray a little in the opening as a test and you will see how it reacts.
 
Didn't you say earlier this problem just started when it got cold?
Hard to say what is wrong sometimes. If one side of the carb reacts and the other side doesnt with the needles. It's probably the carb if you find no vac leaks
 
Yeah it only happens at about 60* or less. The past three days it's been close to 80* (guess our pitiful little fall/winter is over) and it's been running a lot better. That's what initially led me to believe it was related to the choke in the first place.
 
Still could be, proper adj choke is critical. Combination of fast idle, choke break and how long choke transitions to open. I've had a bad electric choke coil go bad and take to long to heat up.

You really need to get book or look up info on the net to check your choke adjustments. Difficult to explain it.
Also every time you move the throttle your pumping fuel into the engine with the accell pump. This will cause hard starting and other things.

Each time you change a choke adj engine has to be dead cold.
Setting your fast idle to say 1600 on a warm engine will only be about 1000 on a cold engine, adjust to what is neededTo keep the engine running cold. Once you get that and you drop in gear and quits (automatic trans)you need to adjust the choke break. That why you need pics and info in front of you.
 
Okay so I managed to get the carb doing a lot better. I noticed that gas was seeping out of the top somewhere. After I took it apart my dear old dad pointed out that the float was way too high, like almost topped out. Not sure how that happened. I hadn't messed with it. He used to a little ruler to set the float to 13/32 and we rebuilt the whole carb. Now it doesn't stall out at idle. I still can't get the passenger's side idle mixture screw to change the mixture setting at all, so I still had to set the idle a little higher than I like. Pretty sure there's some vacuum leaks somewhere. I replaced a few hoses but there's several more that are dry rotted and need replacing when I have time. I'm just glad to have it back running acceptably again.
 
Ok I found it, it's a Q-Jet.
Quick question, will the 4 barrel kick in when you stomp it?
If no, it's the "choke pull off".

I had a QJet rebuilt and put on mine, it ran like crap until I got the pull off working, after spending $30 on a new one it turned out the vac port was plugged. For some reason Dirt Dauber mud can resist 3 days in chem dip, go figure.
 
andyblack said:
Okay so I managed to get the carb doing a lot better. I noticed that gas was seeping out of the top somewhere. After I took it apart my dear old dad pointed out that the float was way too high, like almost topped out. Not sure how that happened. I hadn't messed with it. He used to a little ruler to set the float to 13/32 and we rebuilt the whole carb. Now it doesn't stall out at idle. I still can't get the passenger's side idle mixture screw to change the mixture setting at all, so I still had to set the idle a little higher than I like. Pretty sure there's some vacuum leaks somewhere. I replaced a few hoses but there's several more that are dry rotted and need replacing when I have time. I'm just glad to have it back running acceptably again.
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If you still have no control at all with the mix screw you have a plugged or restricted idle tube or idle channel. Its already lean before you turn the screw in so no effect on idle quality.

Also with that year carb (1985) the mix screws are fine threaded and can require as much as 7-8 turns out, but either way if they or one of them is all the way in you should have a change in rpm.
 
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