Q'jet Fun

[pontiacgp]

I posted about one of my Q'jets flodding last week and thought I found the issue with a metal chip stuck on the needle. Yesterday I decided to try it out and it flooded again just idling. So I opened it up today and tested the float setting by filling up the bowl and checked it. It was fine. I blew into the inlet and the needle held fine but cheching on that people blow less than 1.5 lbs so that test is NFG. I tested it by sitting the carb on the inner fender with the horn off and the fuel line hooked up to it and turning the engine over using my bypass with the ford style solenoid. Held down the rod that holds the float in place the needle stopped the flow when the float hit it's level and it held. I put the gasket and the horn on and tested it again, didn't flood and the float was at the perfect level. The only thing I can think of the carb flooded while the car was running so possibly the fuel is able to sneak by with the slight vibration of the engine running......so next step is to put in a new seat and needle.....🙂

 

[Ribbedroof]

I'm sure you have thought of these already, but 3 things that come to mind right away are

Is there enough arc on the float rod curved section to provide adequate pressure to hold it down when assembled

Float becomes saturated and sinks after "X" time

Fuel pressure...maybe combined with one of the above

 

[DRIVEN]

I had a float that would occasionally touch the inside of the bowl and hang up, causing flooding. Usually happened after sitting for a couple days. I assume that after the fuel evaporated from the bowl is when it would drop. Then the tip (opposite of the hanger end) would catch the wall of the bowl as the fuel refilled it. Make sense?

I shaved the float a bit and it's been fine for over 2 years now.

 

[pontiacgp]

I'm sure you have thought of these already, but 3 things that come to mind right away are

Is there enough arc on the float rod curved section to provide adequate pressure to hold it down when assembled

Float becomes saturated and sinks after "X" time

Fuel pressure...maybe combined with one of the above

I tested the float in a bowl letting it sit over night, both of the other questions were answered when I tested it sitting on the wheel well today without the horn and with the horn, you can also see it indentation of the rod for the in the gasket which is normal , plus my other Q'jet I am using runs perfect. The one that is the problem started out fine the other day according to my A/F gauge and then went continuously richer until it stalled the engine

thanks for your input cause it easy to overlook anything and this is a very basic setup on a q'jet so it has to be something simple

 

[pontiacgp]

I had a float that would occasionally touch the inside of the bowl and hang up, causing flooding. Usually happened after sitting for a couple days. I assume that after the fuel evaporated from the bowl is when it would drop. Then the tip (opposite of the hanger end) would catch the wall of the bowl as the fuel refilled it. Make sense?

I shaved the float a bit and it's been fine for over 2 years now.

I don't think the float is close to the walls but I will look at that....thanks

 

[69hurstolds]

Float level too high? I mean, check the gasket area over the float on the air horn to make sure there isn't something hanging down on it where it may not let the float come all the way up to stop the float from sealing off? (which will never happen with the air horn off)

Just throwing some spaghetti on the walls.

 

[Bonnewagon]

I agree- new needle and seat. Eliminate that as a potential problem.

 

[Clone TIE Pilot]

Try testing the needle valve for leaks with a Mityvac. Sometimes brand new ones can leak. Other possible issues could be too much fuel pressure or stripped needle seat threads.

 

[pontiacgp]

Try testing the needle valve for leaks with a Mityvac. Sometimes brand new ones can leak. Other possible issues could be too much fuel pressure or stripped needle seat threads.

The fuel pump I have now is a new Edelbrock 1721 which is rated for 6 lbs. and my other Q'jet has no problem handling the pressure. Plus I tested the carb using the fuel pump pressure and the needle worked like it should and I let the engine turn over a few times to see if the fuel would work it 's way past the needle. I can leave the fule in the bowl and take the float out the fuel will remain in the bowl until I remove the needle. My engine runs smooth at idle but the frequency must be enough to cause the needle not to sit properly. There is only a few things that can make a Q'jet to flood and not difficult to figure out so I like this little problem cause it's not the usual problem you get. But it's not something I intend on overthinking or losing sleep over. 🙂

 

[pontiacgp]

I picked up a kit today from Napa, I was just going to use the new needle and seat but I figured I might as well change the base gasket so I can make sire everything is sealed. The last guy who installed the base gasket is a friggen idiot, he used something on both sides of the gasket to bond it to the base and body of the carb. Anyway got that cleaned up, changed the seat and needle and used my brass float this time. The float was already adjusted to 15/32 from a previous carb and it's all back together. If I have time tomorrow I'll try it out......🙂