Author Topic: Fuel pooling under secondary hanger - normal?  (Read 2388 times)

Offline Shark Racer

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Fuel pooling under secondary hanger - normal?
« on: October 02, 2012, 02:40:57 PM »
I've never paid this much attention to a q-jet before. So when I was checking for nozzle drip (I have it, or something resembling it), I saw that the secondary rod area (where they pass through the gasket in the air horn) had a pool of fuel. Is this normal or no?

If not - where should I be checking?

Thanks much!

Offline Zac Agee

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Re: Fuel pooling under secondary hanger - normal?
« Reply #1 on: October 02, 2012, 10:09:13 PM »
nozzle drip is on the primary ventura's inside the booster rings and on the brass, fuel gathers on them then drips off its very noticable you shouldnt be able to see any exessive wet/fuel driping from that area unless you have nozzle drip.
« Last Edit: October 02, 2012, 10:12:37 PM by Zac Agee »

Offline Shark Racer

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Re: Fuel pooling under secondary hanger - normal?
« Reply #2 on: October 02, 2012, 11:52:02 PM »
Thanks Zac - is the fuel around the airhorn gasket where the secondary rod passes through normal?

Offline Zac Agee

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Re: Fuel pooling under secondary hanger - normal?
« Reply #3 on: October 04, 2012, 12:33:25 PM »
the holes in the air horn that the seconary rods go thrue lead directly into the main fuel chamber so fuel should only be as high as the float setting... fuel shouldnt be any closer then 1/4 of in inch to the bottom of the air horn, the gasket will be wet in there no matter what but fuel shouldnt be any closer then 1/4 of an inch under the gasket

Offline Shark Racer

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Re: Fuel pooling under secondary hanger - normal?
« Reply #4 on: October 05, 2012, 09:57:53 AM »
This is a late model QJ on a 78 vette and the float setting is set at a 1/4". Just found an old post by Cliff that you should only run the high float setting with non-OEM parts as the OEM fuel pumps flow a lot more.

I guess I'll try lowering the float this weekend.

Offline Cliff Ruggles

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Re: Fuel pooling under secondary hanger - normal?
« Reply #5 on: October 06, 2012, 04:08:48 AM »
Correct, many of the later model fuel pumps had higher pressure.  I'm guessing this was done to circulate more fuel thru the return to keep it cooler, as underhood temps on later model emission vehicles was significant.

I've had customers report fuel pressure as high as 10-12 psi with some applications.  Usually they were having issues, and checked it as part of the troubleshooting.

The later carburetors are fine with higher pressure, 7-8 psi will not bother them in the least.  I run 7.5 psi on my 1977 Pontiac carburetor with a regulator and 140gph pump.  I do have a bypass back to the tank, to keep things happy and take some load off the pump.

http://www.youtube.com/watch?v=6zVdoLR-VzM&feature=plcp

......Cliff

Offline Shark Racer

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Re: Fuel pooling under secondary hanger - normal?
« Reply #6 on: October 08, 2012, 09:49:17 AM »
Thanks everyone. I lowered the float level and the flooding is gone.

I had some nozzle drip and fattened up the mixture, the nozzle drip is now gone.

I still have a binding primary shaft (forgot to sandpaper the shaft, so I'm going to take it out and do that and stop by my friend's machine shop in case it's just a bit more than that). Same problem as another poster on here - the thing returns fine with the motor off but sticks with it running. The primary shaft doesn't rotate smoothly in the bore (even without throttle plates) so I'm going to try to fix that first.

Cliff, I'll be sending you an email in a few minutes so we can cook up another order.