Q-jet flooding bad???
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 1,224
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From: Clarksville Indiana
Q-jet flooding bad???
I have a rebuilt q-jet on my 454 that is on a engine stand. When I crank it to try and start it, the carb starting flooding gas into the cylinders and it runs out the exhaust manifolds. I dont touch the trottle and soon as gas gets to the carb it starts leaking. I pulled the carb up and it looked like the right front corner area was where it was all wet at. Any ideas? stuck float? cracked body?
Team Owner
Joined: Jan 2006
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From: Crossville TN
Did you replace the float with a new Nitrofil unit? If so, did you set the new float to the proper 'level'? It sounds like the float is set too high and prevents the needle valve from sealing off flow. It could also be that you installed the needle valve/clip on the float incorrectly. You will have to remove the top portion of the carb to check that out.
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 1,224
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From: Clarksville Indiana
It was rebuilt in florida and mailed to me. I have no idea as to what parts was used or how it was set up. If its a float level or needle/seat issue, would it pump gas in like that when cranking? Should I be able to see it dripping/pouring in while I am cranking it? I didnt see any gas when I looked down in it but when I pulled the carb up it was wet and dripping bad at the right front.
Melting Slicks
Joined: Mar 2009
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If float is stuck or set incorrectly gas will flow freely, normally out of the float bowl vent. Vent is a tube about 3/8 in. dia. on top of carb. in foward part of front venturi area. The old trick to free a stuck float is to tap on front of carb with the plastic handle of a screwdriver but do not rely on this fixing carb. and please have a fire extinguisher ready. I think 7T1 is correct the top of the carb. needs to come off so you can verify what is going on in there. mds...
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 1,224
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From: Clarksville Indiana
OK what about this.. I hung the carb up where I can see the bottom, I hooked up a fuel line and filled it with gas.. I hooked up my weed sprayer to the hose and pressurized it with a little air and watched it.. its not coming out of either bore where the front small blades are.. its dripping from the area in between them.. up inside that cavity, seems like mostly on the right side, dripping off the little plug but coming from higher up in there.. does that mean anything to anybody?
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Thread Starter
Burning Brakes
Joined: Jan 2009
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From: Clarksville Indiana
Well mike its like this.. I dont know if I will know what the heck I'm looking at when I look! Trying to give more info to try and narrow it down some. Gas is not coming out either tube on top, does that rule out the float? Can a float problem make it leak from where I said? Or can you help me more with what I'm looking for when I pull the top off?
Le Mans Master
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Melting Slicks
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Sorry 71coupe454 I had to leave the computer for a while. If fuel not coming out of the vent it is poss. not just a float problem. I think there are nine screws total to get top off, two are hiding under choke blade. Carefully lift off top while pushing down on the accelerator pump it will try to lift up due to spring under it. tilt top to drivers side when it is up and you can remove accelerator pump rod from lever on top of carb. Keep going. mds...
Last edited by mds3013; Nov 28, 2009 at 03:23 PM.
Melting Slicks
Joined: Mar 2009
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Remove black plastic piece and accelerator pump and set aside. Then lift up float by pivot arm and check for foreign material in seat hole or damaged seat. To set float you will need a float gauge but genarally when you press lightly on pivot arm and seat needle seat in hole, tip of float will be about 1/8 in. or so below top of carb. body. Also you might have the incorrect top gasket give us a picture of it too. This is tough to do over the computer. mds...
Last edited by mds3013; Nov 28, 2009 at 03:31 PM.
Le Mans Master
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From: mount holly NC
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Thread Starter
Burning Brakes
Joined: Jan 2009
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From: Clarksville Indiana
OK heres the gasket pic and also I poured gas in the bowl till the float was up higher than the top of the base, then I blew on the fuel line and you can see the bubbles in the pic.. I guess that can only mean its not sealing, I'll take it out and look for something...
