The Ford Barn

37coop · 03-30-2014, 03:59 AM

I,m from the u.k ,the answer is simple ....ummmm errrrr sorry my brain has gone all fuzzy, I think I,ll pass on that cheers Jim.

Mart · 03-30-2014, 04:19 AM

The economiser valve or power valve as it is also known can fail in two ways. (probably more than that, really, I guess). First is by the gasket being bad, or the valve not the correct shape for the seat. This allows fuel to leak past and gives an overrich condition. I think this would also cause the carb to drain overnight, into the manifold. (not 100% sure on that)

The other type of failure is when the diaphragm ruptures. Now, vacuum acts on this diaphragm to keep the valve closed. The valve in it's natural state is open. Vacuum pulls it shut when the engine is running, and when the vac falls to a pre set level, the valve opens enriching the mixture. If the diaphragm is blown then the valve never shuts properly and the mixture receives the extra enrichment all the time.

Setting the carb on the bench may show up the first problem but not the second.

I think.

03-30-2014, 03:59 AM	#21
37coop Senior Member Join Date: May 2013 Location: kent , u.k Posts: 519	Re: 48 coupe- V8-can bad fuel pump leak gas into the engine? I,m from the u.k ,the answer is simple ....ummmm errrrr sorry my brain has gone all fuzzy, I think I,ll pass on that cheers Jim.

03-30-2014, 04:19 AM	#22
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,752	Re: 48 coupe- V8-can bad fuel pump leak gas into the engine? The economiser valve or power valve as it is also known can fail in two ways. (probably more than that, really, I guess). First is by the gasket being bad, or the valve not the correct shape for the seat. This allows fuel to leak past and gives an overrich condition. I think this would also cause the carb to drain overnight, into the manifold. (not 100% sure on that) The other type of failure is when the diaphragm ruptures. Now, vacuum acts on this diaphragm to keep the valve closed. The valve in it's natural state is open. Vacuum pulls it shut when the engine is running, and when the vac falls to a pre set level, the valve opens enriching the mixture. If the diaphragm is blown then the valve never shuts properly and the mixture receives the extra enrichment all the time. Setting the carb on the bench may show up the first problem but not the second. I think.