VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 1928 Chevy AB: Engine Sputtering and Moisture on Intake Pipe

Hello everyone,

First time posting. Hoping the community may have a solution to my problems. I have a 1928 Chevy AB. When I turn on the vehicle the engine sputters and the intake pipe becomes ice cold and produces condensation.

I just added a new filter to the fuel. The carburetor is clean. The timing is set to 1,2,4,3.

Here is a link to a short video showing the engine with sound. Appreciate the assistance in advance.
https://share.icloud.com/photos/0-DS4DdBilYoDrrMsewqg2Tlw

Werner

Is your flex pipe to the carb connected to the exhaust manifold so it can pre-heat the incoming air?

yes, the pipe is connected

Werner, could be few issues, is your fuel flow clear and consistent, does your shut-off valve in the vacuum tank work properly? a partial vacuum in the outer tank slows flow to the carby. and thus runs too lean, the condensation seems like you have gas under pressure and it is escaping like a hole on the manifold of the vacuum line this causes and endothermic reaction and cools the metal, Though another possibility is you have a valve that is riding and you are getting pressure back through the inlet. Ray

Noticeable cooling of the intake manifold on 4 cylinder Chevys is normal on startup. The gasoline being carried into the manifold is still partially in small liquid droplets. Those droplets require heat to change from liquid to gas. That is how an air conditioner or refrigerator cool. Once the warm air from the stove and flexible pipe heat the air coming into the carburetor and the carburetor body you should find the intake no longer feels cool. During that time the engine will produce some unburned carbon as liquid droplets may not completely burn.

The water from the tail pipe is partly water that condensed in the exhaust system as it cooled from last running. The amount depends on the amount of water in the air being drawn it as the exhaust system cools. Water is also produced by burning the gasoline (hydrocarbon). It is in the form of water vapor that will condense in a cool exhaust system. When the exhaust system warms above the boiling point of water the droplets will cease.

Hi Chipper,
thanks for info. The point is not the cold inlet pipe, it is the sputtering and the sound like running on 3 zylinders only not all the time irregulary.
When the engine starts its running well for a minute than the problems begin.
what to do?????
rgs werner

I have taken all the fuel supp and timing a part, maybe the timing is not correct I´m not sure any help how to do it in the right way??

Thanks Ray, I´ve checked all no changes is it the sputtering see my replay to chipper
rgs werner

Did you hear to the sound on my video??

Did you hear to the sound on my video??

I'm not sure it sounds like a fuel flow issue (to me anyway). It sounds more like an ignition problem. I would check the basics first. Leads and plugs etc. I would also check the points etc. Check the gaps on both points and plugs too.

I'd throw the paper filter you have in between the vacuum tank & the carby 1st.The fuel feed to the carby is by gravity,and paper filters are too restrictive on a fuel delivery system like this.2nd,are you using carbon leads from the coil to the distributor,and from the distributor to the sparkplugs?,if so replace them with copper wire leads.Then,get the engine running after connecting an alternate fuel supply can and a vacuum gauge to the fitting on the inlet manifold,and come back with the reading/s you get.

It sounds like you are having a spark jump in your distributor cap. Fuel doesn't give a consistent skip and miss sound like that. Moisture or carbon ark in cap.

call me 1928 owner with the right anser. the 28 I have needs heated air to breath righ

chevy 1928 national owner my intake manifold turns ice cold as soon as it turns over

That's the atomized fuel/air mixture that is cooling off the intake manifold.

When the engine warns up (and if the heat tube is attached from the exhaust stovepipe to the back of the carb), heated air is delivered to the carb and the intake manifold will warm up.

The engine in my '27 one ton truck (Lurch - see the links below) is a 1928 engine and was started many years ago without the heat tube attached. The carb eventually frosted over and the engine stopped.

Cheers, Dean

There could be an arc burn mark/s as Steve suggests,possibly between the centre carbon button that the spring of the rotor button pushes against between one or more of the terminals in the distributor cap,causing the spark to not go to the correct terminal in the correct firing order.There could also be a crack on the inside of the rotor button where it fits on to the top of the cam,allowing the spark to track to earth intermittently,or even a fault with the low tension power terminal,and or its associated insulation pieces that insulate the terminal stud from the housing as well as the spring arm for the points from the housing.It'd be worth checking the whole distributor to eliminate any faults,or faulty parts.

I,ve checked your points, firing order etc seems to be ok. but the valve clearence was not correct, I,ve adjusted, its running much better but not fine in higher speed,then it gets not enough gaz.I believe. The vacuum in the intake pipe is 0,6 bar. As next I,ll put the carburator in an ultrasonic cleaning device lets see what happens
rgs werner

The vacuum is minus .6 bar of course