a carburetor shouldn't spill fuel like this, right?

[Scott06]

as stated, at 9-10 psi you are likely overcoming the floats. Either different pump with less pressure, or an inline regulator to get that down to 4-7 psi would be where I would start.

Would not add a regulator to overcome a malfunctioning fuel pump

 

[ScottinAZ]

Would not add a regulator to overcome a malfunctioning fuel pump

I would agree, if the pump is specced at the proper 4-7 psi. If however it’s specced closer to 9-10, that’s where I would put in a regulator. OP hasn’t stated if it’s a new pump or the old original that now has an overactive sense of purpose. Either way, he needs to get that rail pressure down some

 

[Scott06]

I would agree, if the pump is specced at the proper 4-7 psi. If however it’s specced closer to 9-10, that’s where I would put in a regulator. OP hasn’t stated if it’s a new pump or the old original that now has an overactive sense of purpose. Either way, he needs to get that rail pressure down some

Merc spec is 4-7 psi which is normal range for carbed engines for the last 65 years. He may have the wrong pump or cheap aftermarket pump that has too much pressure. Carter makes two universal fit marine pumps that put out 4-6 and 6-8 psi respectively. It’s what Michigan motorz supplies on their partial engines. With some plumbing it is a cost effective solution

 

[nola mike]

Duplicate

 

[nola mike]

Merc spec is 4-7 psi which is normal range for carbed engines for the last 65 years. He may have the wrong pump or cheap aftermarket pump that has too much pressure. Carter makes two universal fit marine pumps that put out 4-6 and 6-8 psi respectively. It’s what Michigan motorz supplies on their partial engines. With some plumbing it is a cost effective solution

I'm on my 3rd Carter pump. First put out 8psi, 2nd and 3rd each at 2.5 psi. Which is I guess enough to pressure to fill the bowl. And apparently the pressure isn't related to the volume

Other than the fact that the fuel pressure is too high for a carbed engine, it is possible that on the Edelbrock carb one of the floats can hang up against the inside of the float bowl. I recall a post on this forum about this very problem.
The Edelbrock has 2 floats one on each side. Is this happening on both sides or only 1? If only 1 I’d remove the air horn & inspect the floats.

Shouldn't surprise you that that was me

 

[ShoalSurvivor]

Don't know which V6 other then one with a 4 bbl
Find the original fuel pump was 805656A5, is this the pump your have?

Put a couple gal of old stuff in a full tank and the truck should not have much issue, or run it in the lawn mower, but even the mower can have issues

I have a 861155A3 installed. I believe it is original.

 

[Scott06]

I'm on my 3rd Carter pump. First put out 8psi, 2nd and 3rd each at 2.5 psi. Which is I guess enough to pressure to fill the bowl. And apparently the pressure isn't related to the volume


Shouldn't surprise you that that was me

did the 8 psi pump overflow the bowl

 

[ShoalSurvivor]

The Edelbrock has 2 floats one on each side. Is this happening on both sides or only 1? If only 1 I’d remove the air horn & inspect the floats.

It only leaks on the port side. it's a Edelbrock style but is a weber rebuild: Carter AFB-4.3L-Marine-Electric Remanufactured 4 Barrel 4.3L Marine Carburetor from National Carb.

I'm going to add a regulator and test with fresh fuel before cracking it open or returning the carb.

 

[nola mike]

did the 8 psi pump overflow the bowl

Yes...I think. That was running on the stand, and recurred even after I pulled the carb to recheck the float. So replaced pump. Didn't do it again, but replaced the pump after noticing low psi. Low psi on 3rd pump as well, but said screw it and gave it a shot. It happened again intermittently with the low psi pump #2 after I rejetted the carb, which is how I found the intermittent float sticking. I forget what exactly it was catching on

 

[ShoalSurvivor]

Is there a correct water separator filter and anti siphon valve in place?

Water separator, yes. I have not tested the AS valve but since the pump is flooding the carb, it doesn't seem to be restricting the flow.

 

[Lou C]

I'm on my 3rd Carter pump. First put out 8psi, 2nd and 3rd each at 2.5 psi. Which is I guess enough to pressure to fill the bowl. And apparently the pressure isn't related to the volume


Shouldn't surprise you that that was me

thought so
well that's just Edelbrock's way of making you an expert on these things lol.
like I learned with the Quadrajet
I have a Sierra pump (old style mechanical) on mine that is working fine

 

[ShoalSurvivor]

I would agree, if the pump is specced at the proper 4-7 psi. If however it’s specced closer to 9-10, that’s where I would put in a regulator. OP hasn’t stated if it’s a new pump or the old original that now has an overactive sense of purpose. Either way, he needs to get that rail pressure down some

My current pump is the original OEM pump 861155-3

It's possible that the pump is failing and it increased pressure from 4-6 to 9-10, but it's odd that the aftermarkets all seem to be rated at 9-10psi

 

[ShoalSurvivor]

I'm on my 3rd Carter pump. First put out 8psi, 2nd and 3rd each at 2.5 psi.

Were these all the same part number, just performing differently, or did you order a different pump for the 2nd/3rd orders?

do you have a Carter part num for 4-5psi?

thanks

 

[ShoalSurvivor]

I have a 861155A3 installed. I believe it is original.

I pulled it:
861155-2
2072 A

 

[havoc_squad]

Edited.

Had an old seperate thread and this one mixed up in the details.

 

[alldodge]

Make certain you put the correct model of OEM gasket/spacer when installing mechanical

OP pump is electric, your talking about the mechanical pump

 

[dubs283]

I have not tested the AS valve but since the pump is flooding the carb, it doesn't seem to be restricting the flow.

Understood

My thinking is if someone abated the valve it's plausible (not probable) the lack of restriction from the valve is causing the pump to flow too much fuel/too high a pressure

Only reason I'm thinking this is because I've never seen an electric fuel pump on a carbureted engine fail by supplying too much pressure

 

[nola mike]

Were these all the same part number, just performing differently, or did you order a different pump for the 2nd/3rd orders?

do you have a Carter part num for 4-5psi?

thanks

Same pump

 

[ShoalSurvivor]

I installed a fuel regulator, which brought the pressure to under 6psi.

It still flooded on one side.

I contacted the seller and agreed to inspect. I disassembled and tested the floats, seats and needles. Everything seems operational. Both floats held pressure when manually closed.

After reinstalling, it held for a few seconds, but after cycling the pump, it started to flood again, still only on one side.

The carburetor is going back.

 

[tank1949]

recently purchased and installed a Carter AFB-4.3L-Marine-Electric Remanufactured 4 Barrel 4.3L Marine Carburetor - Electric Choke. Same model, installed easy.

I have been diagnosing fuel supply and bypassed the oil pressure sensor to test the fuel pump.
This is what I'm seeing at the carburetor with the ignition on, without starting:
View attachment 382022
I would expect the float and valve to stop that flow and suspect a problem with this carb.
Is this expected?

thank you!

is pump marine grade or automotive??? I tried to cut corners many years ago by replacing a faulty pump with an auto's. Bad mistake!