
Leaking Holley Carb.
#1
Posted 13 February 2025 - 07:46 PM
Just want some advice on my Holley.
It's a 600 vac secondary, that appears to leak only when left to sit.
While running I can't find a leak and leaving the electric pump running I can't see it either but if I leave the car for a while I find old fuel pooled and going bad/ sticky on the manifold. It's on both sides.
Any ideas?
I believe the pump is running 3 to 5 psi from memory. No pressure regulator in line or return line, would residual pressure in the line cause this?
#2
Posted 13 February 2025 - 08:07 PM
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#3
Posted 13 February 2025 - 09:03 PM
#4
Posted 14 February 2025 - 02:21 PM
If this isn’t happening it means the needle and seat are doing their job ok.
I agree with Clay, probably just weepy gaskets.
Can get weeps coming from the accelerator pump too.
Might be easy to see when the carb is off and upside down
#5
Posted 14 February 2025 - 08:50 PM
#6
Posted 15 February 2025 - 06:02 AM
#7
Posted 15 February 2025 - 09:15 AM
Ran Holleys on cars for years without problem with no pressure regulator.
Its probably not a bad idea to have one, but there would be hundreds of thousands of them operating successfully without one.
Change the needle and seat first.
You can do a full gasket replacement/rebuild in under an hour.
Cheers
Rob
#8
Posted 15 February 2025 - 09:56 AM
For 45 bucks, this probably could also save your car if a fuel line burst under the bonnet. Aeroflo and Bosch units are around $200.
Screenshot 2025-02-15 075415.png 795.73K
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#9
Posted 15 February 2025 - 11:10 AM
#10
Posted 15 February 2025 - 03:56 PM
definitely fuel getting past the needle and seat with the electric pump on
What fuel pump are you using?
#11
Posted 15 February 2025 - 08:33 PM
I was watching it with the pump on amd saw it pushing fuel into the bowls. so I guess i need a inline pressure regulator?
Or the float level is too high?
#12
Posted 16 February 2025 - 05:28 AM
Looked for fuel regs yesterday and could only find ones to suit EFI
#13
Posted 18 February 2025 - 06:24 PM
#14
Posted 19 February 2025 - 11:12 AM
Rochester or Edelbrock (if they still make 'em).
#15
Posted 19 February 2025 - 07:19 PM
Depends on what manifold you have . The 600 will be ok on a small dual plane , if it is single plane go for a 650dp
I have a brawler 650 dp and single plane on my 308 now but before i got the brawler it had a 600 vac holley and was never that good
#16
Posted 20 February 2025 - 10:59 AM
Still need to set float levels.
I have a torque power dual plane at the moment.
#17
Posted 26 February 2025 - 09:34 PM
I'll remove the pressure regulator and see if that helps. as it's the only other change beside the rebuilt carby.
#18
Posted 26 February 2025 - 09:37 PM
Should you choose to enlist professional help at any stage Steve - go and see Eric down at Goody's Garage. He won't rip you off, and he's a guru with these sorts of cars. Loves his carb'd V8's.
#19
Posted 26 February 2025 - 09:48 PM
#20
Posted 14 March 2025 - 10:41 AM
Get it sorted Steve?
#21
Posted 14 March 2025 - 01:21 PM
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