20 replies to this topic

[hawk]

Hey Guys,

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?

[claysummers]

Has to be coming from one of the float chambers. I would start by putting new washers on all the screws, fibre or nylon. If that doesn’t fix it it is easy to take off the chambers and metering blocks, and replace the gaskets. You shouldn’t need to unbolt the carb to do this.


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[hawk]

Thanks, I guess I'll try to buy a kit for it on Saturday. I want to get it sorted before it goes in for its exhaust next Friday.

[Bruiser]

Any excess pressure sneaking past the needle and seat would be pushing fuel straight up and out of the bowl vent tube
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

[hawk]

definitely fuel getting past the needle and seat with the electric pump on

[hawk]

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?

[Rockoz]

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

[Shiney005]

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.

 

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[hawk]

I'll try sus one out later today.

[rexy]

definitely fuel getting past the needle and seat with the electric pump on

 

What fuel pump are you using?

[rodomo]

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?

[hawk]

I just checked the pump, its a proflow 6 to 8 psi pump.
Looked for fuel regs yesterday and could only find ones to suit EFI

[hawk]

Replacing the carb with a changeover rebuilt one. Just need to decide whether or not to go 600 again.

[Shiney005]

Rochester or Edelbrock (if they still make 'em). 

[UCSLE]

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

[hawk]

Thanks guys, just got another 600 for now.

Still need to set float levels.

I have a torque power dual plane at the moment.

[hawk]

Still running pretty poorly with the new carb. it will idle fine and rev fine while stationary but when driving, anything much over idle it's got no go at all.

I'll remove the pressure regulator and see if that helps. as it's the only other change beside the rebuilt carby.

[LXCHEV]

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.

[hawk]

Thanks Brett, they're a 2 minute walk from my work. I'll go see them for a chat on my lunch break tomorrow.

[Shiney005]

Get it sorted Steve?

[hawk]

Yeah all sorted. the new carb had something wrong with it. exchanged it for another unit and the car is running well now.