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Holley tech question for you. #1102077
10/26/11 08:14 PM
10/26/11 08:14 PM
Joined: Dec 2003
Posts: 3,957
West Coast, CA
T
Troy Offline OP
master
Troy  Offline OP
master
T

Joined: Dec 2003
Posts: 3,957
West Coast, CA
Hello everybody, question for you all.

I have a cross ram Hemi and I'm running the stock, 660cfm, vacuum secondary carbs. Everything runs very well but fuel will start leaking out of one or both of the boosters on my passenger side carb.

Here are the things that I have done:
Change needle and seats.
Adjust float level all the way down to the point where it's just about closed.
Pulled that needle assembly out and exchanged it with one that does not leak....and it still leaks.

Info about the car:
Stock Carter fuel pump.
Idles at 950 in neutral and 850 in gear.
No electric fuel pump.

The cool thing is when you turn the the car off it will still leak even after you turn the car off!!

What am I missing!!

Thanks, Troy


....there is nothing like driving my 1968 Hemi Dart around town and having people looking at you like you're nuts!!
Re: Holley tech question for you. [Re: Troy] #1102078
10/26/11 08:23 PM
10/26/11 08:23 PM
Joined: May 2011
Posts: 340
Alaska
7
73rrak Offline
enthusiast
73rrak  Offline
enthusiast
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Joined: May 2011
Posts: 340
Alaska
is your tank vented and is the vent clear and working? I had a similar problem with my challenger. I used a vented cap but the hole for the vent wasn't drilled all the way so it wasn't working. If you drive your car then bring it home open the gas cap and hear a pssssssss then you found your problem. Just sitting in your driveway if it's still hot where you live should help you do the same test.

Re: Holley tech question for you. [Re: Troy] #1102079
10/26/11 08:40 PM
10/26/11 08:40 PM
Joined: Jul 2003
Posts: 1,107
Spring Valley ,Ca.
moparsquid Offline
super stock
moparsquid  Offline
super stock

Joined: Jul 2003
Posts: 1,107
Spring Valley ,Ca.
I had a similar problem with my set-up on my 500 max wedge clone.I noticed that the linkage was not equal and it keept the throttle blades just open enough to leak a bit ,adjusted and no more leeks.

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Re: Holley tech question for you. [Re: moparsquid] #1102080
10/26/11 08:47 PM
10/26/11 08:47 PM
Joined: Jan 2003
Posts: 2,648
USA
M
max Offline
super gas
max  Offline
super gas
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Joined: Jan 2003
Posts: 2,648
USA
One thing I would look at would be the float itself. It could have a hole in it causing it to keep the needle and seat open.
One other thing to look at is the bowl gasket, if might be keeping the float from rising up enough to close the needle and seat.
If none of those are the problem then you might double check the way you are setting the float level.

Re: Holley tech question for you. [Re: max] #1102081
10/26/11 09:50 PM
10/26/11 09:50 PM
Joined: Dec 2003
Posts: 3,957
West Coast, CA
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Troy Offline OP
master
Troy  Offline OP
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Joined: Dec 2003
Posts: 3,957
West Coast, CA
All very good possibilities.

I will check the the gas cap and make sure that it is vented.

The float is the solid, plastic type so there is no hole. I checked the gasket and the float is free of all obstacles.

Float level is all good....I just checked it again. I even have it a bit on the low side.



....there is nothing like driving my 1968 Hemi Dart around town and having people looking at you like you're nuts!!
Re: Holley tech question for you. [Re: Troy] #1102082
10/26/11 10:13 PM
10/26/11 10:13 PM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
float waterlogged, mechanically hanging up in it's range of travel, damaged O ring,need to lube it 1st before installing, fuel psi borderline too high. I'd swap the pri bowls & see if the flooding follows the bowl since you swapped a known good needle/seat & if the O ring is undamaged there might be a prob with the bowl itself.

Last edited by RapidRobert; 10/27/11 10:21 AM.

live every 24 hour block of time like it's your last day on earth
Re: Holley tech question for you. [Re: Troy] #1102083
10/26/11 11:21 PM
10/26/11 11:21 PM
Joined: Jan 2003
Posts: 5,439
So Cal
Sinitro Offline
master
Sinitro  Offline
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Posts: 5,439
So Cal
Maybe the fuel is being pushed due to percolation...
When the engine is shut off and the engine temperature rises it causes the fuel to boil in the bowl and leak out of the boosters. A couple of possible fixes..
1. Adjust the float level down slightly..
But U said this has already been done..
2. Add a thin phenolic spacer under each carb..
This will insulate the carb to keep its temperature lower, and minimize the boiling of the fuel. As today's unleaded fuels seem to have a lower boiling point..

Note that I had a similar problem on my B5 RoadRunner, put a short phenolic spacer (0.125") under the 770 Holley and problem solved...

Just my $0.02...

Re: Holley tech question for you. [Re: moparsquid] #1102084
10/27/11 09:26 PM
10/27/11 09:26 PM
Joined: Jan 2003
Posts: 12,053
Benton, IL.
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DaveRS23 Offline
Special needs idiot
DaveRS23  Offline
Special needs idiot
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Joined: Jan 2003
Posts: 12,053
Benton, IL.
Moparsquid is thinking along the same lines as I am here. Make sure that the throttle plates on that carb are not open a little too much so that they are pulling on the mains.


Master, again and still
Re: Holley tech question for you. [Re: Troy] #1102085
10/27/11 10:01 PM
10/27/11 10:01 PM
Joined: Jan 2003
Posts: 1,996
s. e. pa.
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calrobb2000 Offline
top fuel
calrobb2000  Offline
top fuel
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Joined: Jan 2003
Posts: 1,996
s. e. pa.
hi
what is the list no of your carbs ?

perhaps a leaking power valve ?

what vacuum is the engine pulling warm in gear ?

what no power valve do you have in them ?

a wrong or toren power valve gasket ?

perhaps a bad metering block gasket ?

a float that has become fuel soaked , have you weighed it ?

Last edited by calrobb2000; 10/27/11 10:02 PM.






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