Carburator overflowing

[dan512]

Last week, my car (with a 351 Ford Racing crate engine) went through one tank of fuel in arond 100 miles (no racing, just cruising around) so I thought something was way off.

At home, I opennde the hood, and saw that the carburator (Holley Speed Demon 750) was overflowing, just leaking fuel all over the place. Lucky me the car didn't catch fire.

My mechanic is out of the country this week. Any ideas what the issue could be, as the car runs fine, despite the leak.

Thanks!

Dan

[RockBit]

The first thing I would check is the float. If the float has a hole in it and is filled with fuel, it cannot shut off the flow from the fuel pump when the bowl is full. If the float is not leaking, it may be some debris under the float needle, which could also cause the overflow.

Be very careful that you don't have the car catch on fire. I would not drive it until you get this sorted out. Good luck.

[Gaz64]

Hi Dan,

I would have your whole fuel system inspected, and possibly redesigned if necessary.

What fuel pump?
How much fuel pressure, do you have a gauge, has the pressure ever been measured?
Does it have a pressure regulator?
Filters pre and post fuel pump?

And as Chris has mentioned above, more than likely a delaminating fuel hose near the carb, that line debris is jamming a needle off it's seat.

Seen this too many times to count.

Gary

[fastd]

i think we need more details.

was it fuel boil after a 30+ minute drive? how much fuel overflowed? for how long?

a typical problem is heat from the engine boils the fuel in the bowls after you shutdown the engine...is that what happened?

[wkooiman]

What RockBit said.

Most likely it is debris in the needle/seat, especially if it was running fine previously. The debris prevents the needle/seat from being able to close off the fuel supply. The float bowls fill up with fuel, and fuel spurts out of the boosters and the vent tubes if it is really bad.

When you shut it off, it leaks fuel until there is no more fuel pressure in the lines, and guess what? That fuel goes past the rings and into the oil pan. So, you may want to change the oil too. Check the oil, and see if it is reading too high or if it reeks of fuel.

The fix is fairly simple. Remove the needle/seat, clean, and replace with new if you suspect that the seat was damaged.

You should also question how the debris got in the lines in the first place. Was something recently changed in the fuel supply? New hoses? New filters? If nothing changed, where did the debris come from? Is the filter effective? Are the fuel lines old and falling apart?

[dan512]

Originally Posted by Gaz64

Hi Dan,

I would have your whole fuel system inspected, and possibly redesigned if necessary.

What fuel pump?
How much fuel pressure, do you have a gauge, has the pressure ever been measured?
Does it have a pressure regulator?
Filters pre and post fuel pump?

And as Chris has mentioned above, more than likely a delaminating fuel hose near the carb, that line debris is jamming a needle off it's seat.

Seen this too many times to count.

Gary

It's a Holley fuel pump, no clue what model. Pictures attached.

Pressure regulator is present in the engine bay just before the pressure gauge. Pressure reads around 9psi.

I read in the Holely card manual it should be 6-7,5, so I will dial that down.

Haven't seen a filter yet.

Dan

[Gaz64]

Can you post a pic of regulator and gauge?

Is the gauge liquid filled?

And 9 psi is too much.

Have you checked the float levels lately?

[dan512]

Thanks for all the tips.

Carb overflow is fixed. Pressure dialed down and I found a fuel filter.

Engine still seems to be running a bit rich, my mechanic will look into that soon.

[Gaz64]

Originally Posted by dan512

Last week, my car (with a 351 Ford Racing crate engine) went through one tank of fuel in arond 100 miles (no racing, just cruising around) so I thought something was way off.

At home, I opennde the hood, and saw that the carburator (Edelbrock Victor Jr.) was overflowing, just leaking fuel all over the place. Lucky me the car didn't catch fire.

My mechanic is out of the country this week. Any ideas what the issue could be, as the car runs fine, despite the leak.

Thanks!

Dan

Hi Dan,

Is your carb an Edelbrock, or the manifold or both?

A Victor Junior is an intake manifold.

Gary

[dan512]

Originally Posted by Gaz64

Hi Dan,

Is your carb an Edelbrock, or the manifold or both?

A Victor Junior is an intake manifold.

Gary

I messed up. It's a Holley Speed Demon 750

[fastd]

i am wondering how/why the psi got up to 9...?

[dan512]

Originally Posted by fastd

i am wondering how/why the psi got up to 9...?

No clue, the car ran fine last year, put it away for the winter, took it out again and the carb jet threw fuel all over the place.

Well it's fixed now, but I'm still weary and pulling over now and then to check it's really still fine. Could have have a very bad ending.