Stormberg vent leak

[MGDAD]

A friend gave my
daughter a 1975 MGB on labor day last year. This weekend was our maden voyage, after Paint,Uhpolstry,rework suspension,all done in our garage with her help. The car sat in a field for 13 years. OUCH I have rebuilt the carb and when the key is turned on fuel squirts out the bowl vent. I cant figure it out??? Ready to buy a weber? anyone have a idea? I have set the float level,installed a regulator,still squirting, Im giving up. what model weber works?
Thanks, MGDAD

 

[DrEntropy]

First, welcome to the forum!

Is the fuel pump an SU? If not, what pump and what is/why the regulator?

If it is coming out the vent, the needle/seat aren't mating for some reason. Is the float intact? 13 years in a field would have affected any/all the plastic bits. A "quick-n-dirty" method of checking to confirm the needle is shutting off at the right float height is to blow into the fuel inlet as you raise the float to its shut off height... obviously with the carb off, emptied and apart. They're a simple device compared to the Webers.

When you say "rebuilt" the carb, what needle/seat did you use to replace the original?

You ~may~ have luck just replacing the Stromberg with a DFV/DGV Weber but it seems a "baby/bathwater" answer.

What manual(s) have you on hand to use for a guide?

There is a boatload of folks here with decades of experience with these cars, many suggestions will come and soon. HTH.

 

[MGDAD]

Thank you for the welcome and help.

The fuel pump is aftermarket don't know the make it is small square and gold.
I installed the fuel regulator thinking that the inlet pressure was too high. no change in condintion.
So I removed the regulator.

I reinstalled the carb in the car, removed the float bowl and the floats and valve seemed to opperate properely.I replaced the valve with the old one and no change. I would hold the bowl and gaskett to the bottem of the carb and it would fill and shut off like it should. when I would install the screws and create a air tight vessel the fuel would squirt out the vent even before the bowl would fill.

It acts like the vent inlet is inside the brass tube that extends from the main jet to the bottem of the float bowl, and acts like a straw pushing fuel out the vent.

I have the float adjusted as per the manual 5/8 to 1/2 from the bowl flange to bottem of the float.

I removed the float and tested with water, no bubbles or uneven floating, there is no liquid in either float.

Wanted to make sure that the float is not being hung up on anything,trimmed the gaskett of any excess matteral.

I even adjusted the float low so the fuel would not pass the valve and then remove the plug from the bottem of the float bowl and push up the float letting very little fuel in and the same condintion?


I have tested and tried this thing nine ways to sunday and have no idea what is going on. Im sure i will feel stupid when it is figured out.

Thanks for the help D.Ridge

 

[Nunyas]

sounds like the float is not raising enough to shut the inlet. One of the confusing things that caught me out w/ the ZS is you make your float adjustments upside down....

So, initially, most people's instinct is to make adjustments in the wrong direction in an attempt to make it shut off sooner...

hope that helps in some way...

 

[DrEntropy]

Sounds like you've taken most of the "usual suspects" into account.

If you determined the float has no fuel in it (visually), it is likely not the issue... BTW: water will not reveal a pinhole float breach. Gas will find its way into a hole where water will <span style="font-style: italic">not</span> penetrate. But <span style="font-weight: bold"><span style="font-style: italic">milk</span></span> will. Old-school trick. :thumbsup:

From your last description it seems the vent to the vapor cannister may be plugged. Because the thing was exposed to "nature" for a decade, I'd be looking for crazy stuff like mud dauber evidence in the passage(s). No ZedS here to inspect but ISTR the bowl's vent passage starts on the face of the intake. Is that where it spews out? Have you run an aerosol carb cleaner thru <span style="font-style: italic">all</span> the visible holes? Just tryin' to think outside the box here.

I have tested and tried this thing nine ways to sunday and have no idea what is going on. Im sure i will feel stupid when it is figured out.

As will we all, methinks. :wink:

 

[MGDAD]

Plugged vent line at canister, PROBLEM SOLVED
car is running 95% better! more tuning to come

Thanks, D.Ridge

 

[DrEntropy]

WOOHOO!!! :thumbsup:

The pump is likely a low pressure Facet. Should be a dependable unit.

Now DON'T be a stranger! :laugh: