21boy

Just rebuilt the carb because float got stuck, now when you want to turn it over you have to dump gas, and if you take foot off of gas when it's finally turned over it stalls out. When it is running you can smell gas and out of the exhaust greyish-blue smoke comes out. What would be the diagnosis? Oh and its a 74 350 auto trans if that matters. Any help appreciated.

0Paul Ruggeri

You need to be a little clearer. When you say it won't turn over , do you mean when you turn the key nothing happens, or does it turn over but not start? What do you mean dump the gas? Does it start and then stall? Is it flooding? What happens if you keep your foot to the floor when you try to start it?

markids77

Factory Quadrajet? Holley 850 double pumper? Carter Thermoquad? Barry Grant Dominator? What is "rebuilt" and what parts did you use? Have you set the mixture screws back to the settings you wrote down before you took it apart, and set the float height the same way? Need more input. I get that it will not start but "dump" means pump the gas pedal 100 times or force feed 1/2 cup down the primaries with a funnel?

63Nova

Yeah, too much info missing. My initial thoughts are you didn't set the mixture screws and didn't measure the floats.

calwldlife

he has at least 1 thread on his probs with carb.

wer2xu

when you turn the key the starter will not turn the motor? or the motor wont start, I am confused.

21boy

That was from the rebuild, almost a month ago now :o

Its original quadrajet, I replaced the upper gaskets, and most parts that have to do with the float. When you turn the key the starter will turn the motor, but it isn't starting the engine. And on the off chance that you do, by flooring it, the gas will need to be held in for it to stay started. When you take off the gas, it dies instantly.

Oh I rebuilt the carb because the small pin holding the float to the plunger had fell off and the quad would just leak gas like a shiv (spelling?). But I don't believe I touched the mixture screws when I rebuilt it but its possible that they could have been tampered with since the carb was moved a lot.

Hope I didn't miss anything, but there's been a lot of stuff breaking lately and I honestly didn't expect the car to even crank. When it did I made a new thread, forgetting about the one a month ago and I severely underestimated the info that was needed to solve the problem. Sorry.

jeff79'

Turn the fast idle screw in until the tach says 600 under load and warmed up. You won't have to hold the pedal down after you do that.Is your choke working?....Look at the carb when it's cold and pump the gas once...If the choke butterfly snaps shut, then it works.When you turn the key to start the car it should open 1/4 "......Start there and report back Vette cadet...

markids77

OK. So you took the carb off the car, having ordered a complete rebuild kit from NAPA or somewhere before disassembly. You removed the pin for the accelerator pump. the top screws and then the air horn. Did you quit there, or take all (from memory only) 126 pieces out of the carb, soak each in a good cleaning solution and then , following the instructions contained in the kit, reassemble it all the while being mindfull of how to set the float level, and how to adjust the cam on the accelerator pump, and where to "baseline" the high and low speed mixture screws in the carb base? Or what.... please explain.

21boy

I'm afraid I took the easy way out and just stopped at the air horn. Then I found a big enough bucket to handle the rest of the parts still together, dumped enough cleaning solution in to cover it to the top and let sit for about a week, shaking lightly when needed of course.. But I set the float the same as the original had been, so as for the mixture screws I didn't really touch them. I suppose the float could be set wrong if the original had been warped or moved somehow.

I will check back tomorrow afternoon with results Jeff, er.. Sir, yes sir.

markids77

OK. Now it's decision time... buy a full kit and start over... following the build sheet EXACTLY, or farm the job out to a pro. The Q-jet is a really nice carburetor but it is not very tolerant of partial rebuilds... too many tiny airways and jets and stuff. Only you can decide if you have enough tools and knowledge and patience to tackle this and have it work... FWIW my first quadrajet rebuild took a full week of after work labor and I still needed a local pro to finish setting it up. Good luck!

calwldlife

I mentioned the other thread because people tried real hard to help.

You have not done your part to research and get info about

things told to you.

Now you want us to guess why your car is FLOODED.

You need to get a book about the carb and how to set it for initial
use.

You went round and round with people about your float and you were sure
it was fine.

Or save money and have your carb rebuilt for you.

21boy

Thanks for the input, but I'm not looking for a kidney just an opinion and one that you don't have to give if you don't want to.

As for my last post, yea I talked a lot but I also replied to every person that asked me something, tried to assist the people who where helping me, and was courteous as I hope I am now. And for a time everything worked as it was expected too, then unexpectedly it didn't. But thanks for the concerns, have a nice day.



I'll try adjusting the idle screws first tomorrow then I'll take if worst comes to worse I'll disassemble it fully and clean it up. Thanks guys.

SIXFOOTER

Dude, Idle screws ain't the plce to start. Yank the carb off and start over. Completely disassemble the carb, blow all the passages with air and reassemble it according to the sheet. THEN get on with the troubleshooting. Might brush up a bit on the terminology a bit, cranking, turning over, start, stall etc....

Ironcross

I suspect from your information that the float problem was not fixed by the re-build....A easy way to see if that is true is by turning the carb over so the base is up, air horn down and blowing into the fuel inlet. If you can blow through the carb the float issue is still there and the main problem to correct......

What turning the carb over is simulating is a full float bowl. If the float is working correctly you will not be able to blow air into the carb...because the float is correctly seated....saves tearing the carb apart... .......men

alswagg

did you seal the welch plugs after soaking for a week? I am sure you did not remove the plugs, but they do leak if not resealed. I service many carbs in the spring all from Q jets to Holly's to Rochester 2 bbl. easy clean ups do not need to soak for a week. Allan

21boy

I do agree that terminology probably wasn't one of my assets at 12:00pm when I decided to talk about this.
And yes, that does sound like a more reasonable way of proceeding, to fix the problem instead of try to mask it.

I'll give that a go first off. I'm guessing a can of compressed air or very low compression is better off so nothing blows out? Thanks.

Did I seal the welch plugs, no but I'm sure it wouldn't hurt seeing as it did sit in solution for awhile and if I do need to rip it then why not check everything.

Thank you guys, I think I'll go from here. Appreciate it.

Ironcross

blow into it as if your blowing through a straw...connect a line or hose to the carb inlet. no need for anything fancy or compressed air. ..just turn it over and blow into it...

7T1vette

If you left the needle valve and seat in the cleaner for a week, the needle valve seal is "toast" and the fuel won't shut off when the bowl is full. You need to take the carb to someone who knows about carbs...or perhaps someone who has just read a manual about rebuilding one.

nitronick

That right there sounds like a vacuum leak somewhere. A pretty major one. Have someone put their hand covering the air horn of the carburetor and see if she starts.