All Small Six Weber 32/36 rough idle

[Frank]

Everything is only four months old and the longest down time I had was a week. The fuel filter is before the fuel regulator and its a metal one from Napa. Sadly I don't have ethanol free gas here.

Im having such a hard time diagnosing and figuring this car out because damn near everything but the engine itself have been replaced and it will run great then horrible out of nowhere

not questioning your diagnostics ability- are you sure it's carb and not ignition?
Is your regulator a return-line style? Mechanical pumps with the metal fuel line over the engine can develop 15psi from gas expansion, not-return regulators can't hold that back. Gasoline begins boiling @ 150*F, it's going to expand no matter what. Insulating the fuel line has helped hot-soak issues on my vehicles by keeping the fuel cooler. Check Amazon.

 

[beanmiester]

not questioning your diagnostics ability- are you sure it's carb and not ignition?
Is your regulator a return-line style? Mechanical pumps with the metal fuel line over the engine can develop 15psi from gas expansion, not-return regulators can't hold that back. Gasoline begins boiling @ 150*F, it's going to expand no matter what. Insulating the fuel line has helped hot-soak issues on my vehicles by keeping the fuel cooler. Check Amazon.

Please do question it . This car is my only experience with this so other than this forum and my grandpa i don't know what's going on. I think its not ignition. I have 14v at the battery. The dui is getting the power from the battery and needs relatively low amperage. It starts right up each time as well so I think the ignition is fine.
The regulator is a non return style but the vast majority of my fuel line is rubber because of how the weber has to be mounted on the engine. I have maybe 8 inches of steel line coming out of the pump and the hottest it got ever was 135. Thats after idling for a long long time with the ambient temp being 110 that day. My electric fan keeps everything at a reasonable temperature in normal idling conditions. I don't know if temp is the issue because I was having this new issue only a minute after start and thats not long enough for my hoses and carb to heat up to the point where gas would boil

 

[62falcon wagon]

Have you checked your float level in carb? I installed a new Weber idf and it was acting real squirrelly. Pulled the top and took out the float to inspect and the droop arm was going up instead of down and the float level was way off. Googled and found my specific carb adjusted by a guy who knew what he was doing. New carb also had a little trash in jet. New systems tend to get little pieces of rubber in them from cutting fuel lines. Put it back together and huge improvement. There are a couple Weber Gurus on u-tube. Been messing with carburetors for over 50 years BUT 1st time Weber. Sometimes the bowl was filled properly and sometimes not also some regulators have a rubber vent plug that needs to be removed till pressure is set then replaced.

 

[62falcon wagon]

I have rebuilt autolite, Carter, Holley, Amal Delorto, zenith, mikuni, Rochester, boat, lawnmower, snowmobile, chainsaw motorcycle etc. Every one is a little or a whole lot different.

 

[beanmiester]

Have you checked your float level in carb? I installed a new Weber idf and it was acting real squirrelly. Pulled the top and took out the float to inspect and the droop arm was going up instead of down and the float level was way off. Googled and found my specific carb adjusted by a guy who knew what he was doing. New carb also had a little trash in jet. New systems tend to get little pieces of rubber in them from cutting fuel lines. Put it back together and huge improvement. There are a couple Weber Gurus on u-tube. Been messing with carburetors for over 50 years BUT 1st time Weber. Sometimes the bowl was filled properly and sometimes not also some regulators have a rubber vent plug that needs to be removed till pressure is set then replaced.

I have not. I got it from vintage inlines and supposedly from what I've read the float and jets should be set for a 200. Ill take a look when I get the chance though. As for the regulator the instructions just said to make sure its installed the right way for in/out. I made sure for the regulator and the fuel filter

 

[beanmiester]

Oh I should also add my engine has been having rich condition issues even with the autolite carburetor. Like evey carb ive put on there will not lean out without seriously hurting how the engine runs. I've used 5 different autolites 3 new and 2 remanufactured. We even checked the float and jetting on the autolites. Thats not why I went with a weber but maybe that information is useful

 

[Frank]

Oh I should also add my engine has been having rich condition issues even with the autolite carburetor. Like evey carb ive put on there will not lean out without seriously hurting how the engine runs. I've used 5 different autolites 3 new and 2 remanufactured. We even checked the float and jetting on the autolites. Thats not why I went with a weber but maybe that information is useful

That tells me right there- it's time to check your fuel pressure. Mechanical pumps can get old and make high or low pressure. Also, over 50% of aftermarket replacement chain-store pumps are faulty, most too much pressure, mine, barely 3psi.

 

[beanmiester]

That tells me right there- it's time to check your fuel pressure. Mechanical pumps can get old and make high or low pressure. Also, over 50% of aftermarket replacement chain-store pumps are faulty, most too much pressure, mine, barely 3psi.

Any brand you use? If not I'll just keep buying and returning napa pumps until one works

 

[DON]

You need to put a pressure guage on it. A lot of vacuum guages have a pressure side and are pretty cheap. Either that or preferably plumb one in at the carb and leave it

 

[beanmiester]

I ordered a guage to put before the carb. I was just wondering if anyone had a brand of pumps they go with

 

[DON]

I think Carter is starting to make them in the USA. A lot of guys have gone electric

 

[Engine Fan]

Unless the regulator failed how likely is it that the needle and seat are having issues

All it takes is a small piece of debris stuck between needle and seat.

 

[63 Sprint]

A lot of guys have gone electric