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Discussion Starter · #1 ·
It starts fine in the morning. If I start it within a few minutes after shutting it off, it starts fine. After about 10 minutes, it's a bear to start and takes about 10-15 seconds of cranking than ends with a puff of black smoke when it does start. This would include most starts during the day. I'm fairly sure it's some type of choke problem. (right?) It does have an electric choke.
Quadrajet gurus, PLEASE enlighten me!

'86 CJ-7, 360, TFI, 727, OEM Dana 44 rear w/Truetrac, Dana 30 w/Powertrax No-Slip, 4" Superlift, 4:11s, Warn HS9500i
 

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definintely make sure the choke is all the way open when the motor is hot.
Also, you may want to look at it (the choke) opening after you put power to the inginiton wires and the motor is warm, some of them open slowly and may take 5 to 10 seconds to open fully

/wwwthreads_images/icons/cool.gif Big Ed
'88 YJ, 4" susp,3" body,35's,283 Chevy V8,TH350,4.11's,D30,D35c
 
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Sounds like you're on the right track. IMO, the only way to go is a manual choke or none at all. The stock setups seem to cause trouble sooner or later.

/wwwthreads_images/icons/cool.gif
'84 K20 driver
'80 CJ-7 BBC, 1 ton
'79 K10 mud racer (for sale)
 
G

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I don't think it is the choke. You are experiencing what is called a 'hot-soak'. The heat from the engine gets conducted up the manifold into the carb and causes the gas in the float bowl to boil. The boiling gas pushes itself up the jets and essentially floods the engine. The Qjet has some features which are supposed to combat this. The first one is an extra thick gasket between the throttle body and the top of the carb. The second one differs between differant years. Early carbs had a little flapper that opens on the air horn that vents the bowl to the atmosphere when the throttle is closed. This keeps boiling fuel from getting pushed into the throat. This was discouraged by the epa and went away in post- 1970 or so vehicles. They went to a tank return system which should keep the temperature of the gas cooler.

What you can do about it:
1. If you have the flapper, make sure it opens when the throttle is in the idle position.
2. Check your float level. Run it as low as you can before it cuts out when you are off-camber. If you already did this, proceed to step 3.

3. Install a phenolic or wood spacer between the carb and manifold. This will cut down on the heat conducted to the carb and should fix the problem. Jeg's and larger performance parts stores have them.

4. If you are still having hot soak problems it will start better if you floor the pedal and crank for 5 to 10 seconds or so, and then try to start it normally. This will clear the rich mixture from the engine and is the correct way to start the engine after you flood it. DO NOT pump the pedal.

The Qjet has a very good and trouble free auto choke system, and I wouldn't mess with it if it starts well when cold. Most QJets will not start at all cold unless they have a choke.

Regards,
Josiah

Hillsboro, OR
1955 Willys CJ5 Buick 225 V6 160HP 270ft-lbs, T90 trans, Warn OD, PTO winch, Spicer 18 T Case, RS9000's, Dana 25F/ 44R,
5.38:1 gears, 11" brakes, Bestop Supertop, Hurculiner
 
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Could be heat soak, but sounds more like a choke problem to me from reading your post. Doesn't seem like it would be heat soak after only ten minutes. More likely after shutting it down hot. (unless it gets THAT hot in AZ in ten minutes/wwwthreads_images/icons/smile.gif) I'd check the choke first. A phenolic spacer is a great idea regardless. I know Mr. Gasket has them, and they're usually available in 1/2" or 1" thickness.

By the way, my jeep and race truck have q-jets with the choke systems removed and start OK - even in IL winters.

/wwwthreads_images/icons/cool.gif
'84 K20 driver
'80 CJ-7 BBC, 1 ton
'79 K10 mud racer (for sale)
 

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/wwwthreads_images/icons/smile.gif Willie, Willie, Willie.......don't TOUCH that choke./wwwthreads_images/icons/tongue.gif What you have here is a failure to recirculate!! Somehow, and only HE knows how, you have disconnected, plugged, or otherwise disabled the FUEL RETURN line to the tank. The excess pressure is pushing past the needle valve and filling the intake manifold, hence the RRRRRRRRRRRRRRR.....RRRRRRRRRRRR.......CHUG! CHUFF! CHUG! SMOKE! SMOKE! SMOKE! Been there...done that. A Suburban I bought had the return plugged and guess what it did? Yep.....just as you described./wwwthreads_images/icons/crazy.gif

CJDave
Quadra-Tracs modified While-U-Wait by the crack moonguy/wwwthreads_images/icons/wink.gif Quadra-Trac Team./wwwthreads_images/icons/tongue.gif/wwwthreads_images/icons/smile.gif
 

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Discussion Starter · #7 ·
CJDave- That DID in fact happen. When my motor was built, the mechanic said that it would run better and start easier without the return line hooked up. The Holley I had on there for a while ran fine and started instantly every time. It just wouldn't run at angles!! This line ran from an extra fitting on the in-line filter to the tank. Is this the one? I DO have the bowl vent hooked up to the cannister.
Thanks!

'86 CJ-7, 360, TFI, 727, OEM Dana 44 rear w/Truetrac, Dana 30 w/Powertrax No-Slip, 4" Superlift, 4:11s, Warn HS9500i
 
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