Dr. Holley needs helps with a Q-jet

[prostreetC-10]

Had a guy give me a bunch of carbs if I could just get his Q-jet to quit spewing gas out of the accel pump shaft. My immediate first thought was just to replace the pump arm assembly but then I started thinking that a bad diaphragm wouldn't cause that.

When the float level is set too high or there is a problem with the needle and seat not closing on these things, do they tend to shoot out the pump arm hole in the top? Seems that since fluid will always follow the path of least resistance, that would make sense. Thanks!

[cableguy0]

Is it running bad otherwise? Is the carb flooding the engine? I think your on the right track with the float. I would pull the top off and make sure the float isnt sunk. I assume stock fuel pump etc? Is it leaking from anywhere else?

[prostreetC-10]

What's funny about this "deal" is that I was handed the carb. Never seen it on a motor. Just what the guy said. He gave me 5 carbs and asked if I could fix the problem with the one in return. I even told him that I would have no way of testing it once done because I don't have a spread bore setup to test on. I think I'm just gunna "pop the top" and have a look see. Even if the diaphragm was bad, it should recirculate in the bowl and not have enough force to shoot out the hole for the pump assembly....I would think. I'll probably see a jacked up float or a turd in the N/S assembly when I pull it apart.

Thanks Mr. Cable

[hotrod 80]

Probably the float or needle and seat .

[cableguy0]

Nothing like jumping in head first with your eyes closed. Hopefully you can find the "smoking gun" its so hard to fix stuff without actually seeing what its doing wrong. Good luck, I'm gonna bet you find bad needle and seat or a float with a hole in it.I would double check and ask the guy what he was using for a fuel pump though. Make sure it wasnt an issue with too much pressure.

[hotrod 80]

Been a while since i been in one , but i remember a ball bearing type check valve for the accelerator pump that is tempremental about seating some times . Maybe im way off though .

[prostreetC-10]

Originally Posted by cableguy0

Nothing like jumping in head first with your eyes closed.

I love these deals because I told him I would "look at it" and had no way of testing it when I was done. I'll see what I can do and that is that. It's about free to him because he was not into the carbs he gave me.

Funny side note: I build a little 600 for a guy over the weekend just for fun. He barely was able to make it to my house, his bronco was running so bad. I wasn't really happy with the throttle position to get the thing to idle. Up there a ways in the trans slot. Decided to throw my light on the balancer. This guy's inital was literally at TDC!! To top it off, the guy had his vac can on his brand new MSD plugged. Imagine driving around all day at TDC plus just a little mech advance. Just to be "safe" I put him at about 14* and hooked up the advance can. The guy about crapped at how good it ran. It's amazing how many really successful carb rebuilds I have by properly setting their timing!!! LOL

[hotrod 80]

Originally Posted by prostreetC-10

I love these deals because I told him I would "look at it" and had no way of testing it when I was done. I'll see what I can do and that is that. It's about free to him because he was not into the carbs he gave me.

Funny side note: I build a little 600 for a guy over the weekend just for fun. He barely was able to make it to my house, his bronco was running so bad. I wasn't really happy with the throttle position to get the thing to idle. Up there a ways in the trans slot. Decided to throw my light on the balancer. This guy's inital was literally at TDC!! To top it off, the guy had his vac can on his brand new MSD plugged. Imagine driving around all day at TDC plus just a little mech advance. Just to be "safe" I put him at about 14* and hooked up the advance can. The guy about crapped at how good it ran. It's amazing how many really successful carb rebuilds I have by properly setting their timing!!! LOL

My 49' is the same way , bone stock vortec with 600 edelbrock & hei . I took it in to get some warranty work done on the paint . I go to leave in the truck after the repair a week later and it won't hardly even run . Headers are about to melt . I go home grab my race track bag and come back . Timing set at 6 degrees after tdc and idle mixers all the way in and cracked off seat . Im like WTF ! Kid comes out of the back and says "do you like it ?" . Im like "like what ?" He says " i adjusted everything for you and now it sounds like it has a cam ". I tell the owner don't ever let them mess with my truck again . Headers are now blue .

[joes50pu]

Sounds like you have a bad float "heavy causing the float level to be too high". You also could have a bad needle and seat but you'll get that with a new rebuild kit. The check ball someone mentioned is below the accelerator pump and just keeps the gas from draining back into the gas chamber below the float. No check ball means no accelerator pump squirt.

[prostreetC-10]

lol. I'd have said if I wanted it to sound like it had a cam I'd pull off a spark plug wire.