VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Runing too rich

So, my 34 chevy std is running too rich. I mean it is smoking fuel and i can get it leaner. I checked the metering rod and it seems right according to the book. I checked everything including the float level and everything seems o.k. The only other thing i can think of is the aftermarket electric fuel pump that might have a pressure too highfor the carbie but the needle and seat should take care of that right? Oh yes, one other thing.... The airscrew doesnt seem to have an effect. I screwed it in all the way and even removed it completely. When its out you can hear a difference but not too much either. Any help please

The position of the metering rod must be syncronized with the throttle opening. There is a tool for that - see shop manual.
Try running it with the fuel pump disconnected and see if it acts too rich. Should run for a minute with no fuel pump.

Not necessarily. Depending upon the electric fuel pump pressure it can override the needle and push gas through into the carburetor causing either a rich mixture or a flooding condition. However, in this case, most likely the problem is in your carburetor.

By the way, did you have this condition before the electric fuel pump was installed?

My best guess is you have more than one problem.

If the electric pump is pushing fuel past the needle & seat it will eventually flood. That is it will either overfill the float bowl so it leaks gas onto the engine or push enough fuel to choke the engine with fuel so it will black smoke or not run.

Running too rich is more likely not the fuel pump. The head design places the spark plugs where there is a leaner mixture at the plug. That is why the increased spark plug gap and timing helps those engines run better. Increased gap or hotter plugs may help.

You definitely have a problem with the carburetor. The idle mixture adjustment should make a noticeable difference. A passage could be plugged, incorrect internal parts could have been installed, the casting may be damaged, etc. Even if the metering rod is correct the main jet may not be. Also as Gene pointed out the coordination of the metering rod and throttle plate are critical to the carburetor operating properly.

Thank for the reply everyone. Ive disconnected the pump and ran it without it and sure enough, it still runs rich. I will open up the carb and see if there are any passages that's pluged. Could defective points also have this effect? I installed the plugs as it came from fillingstation. I assumed the gap is ok. The car runs and revs fine just smoky which is annoying. I would agree that it is the carb seeing that the airscrew doesnt make a difference. I checked all jets inside that i could find but i must admit there seems to be very few jets inside and not as much as the book says. Or I couldnt find them all. Any pictures here please?

From what you describe it sounds like your carburetor is an excellent candidate for a quality rebuild. A restoration of your carburetor will probably cure your problem.

Points and spark plugs could be part of the problem in addition to the carburetor. I suggest fixing the carburetor first.

I got the rebuild kit from fillingstation. My idea was to rebuild the carb. On receiving the kit i was surprised with the contents. Not much in there. A few gaskets and coper seals. I replaced the pump unit but honestly dont know where the other two check valves goes. Thought there would be instructions but nothing.... I bought another carb from ebay but it was totally rusted and the jets on the inside was totally rusted stuck... Bummer. I build some of my carb over and fitted the new carb but no luck. The car ran good for 5 seconds and died of starvation. I know it's starvation because if i choke it by hand it kept running another 5 seconds. The float was full but couldnt get it to run for longer than 5 secs. Any pictures where theose check valves go.

The two check valves are for the accelerator pump circuit and should not have an effect on running at a steady speed.
You can go to the old car manual site and look at a later shop manual.The 1942 shop manual has good illustrations of the various circuits in the carburetor and may be of some help in pin-pointing the problem. The basic carb. circuits were about the same up through 1948.

If you need manual assistance I could send you the pictures,text from the 1942 manual but will need your email address for that.

Do you mean that the float was full of gasoline? If so, you will have to either replace the float or drain the gas from the float and then lightly solder up the leak.

Sounds like you might need to send your carburetor to a quality rebuilder.

Yep, the reproduction carburetor repair kits are disappointing since they do not have many "hard" parts included in the kit that are needed for a major rebuild like the old Carter repair kits. The old Carter kits had everything needed including the metering rod, throttle rod, pump arm and etc.

I suspected he meant the float bowl????????????

He probably did mean the float bowl but that is not what he indicated, so we can only go by the specifics as they are stated.

I had a similar situation on a F__d. I removed the carb screw that made little or no difference when I turned it and blew a quick blast of air from my compressor into the screw hole. (Stop laughing) I never had a problem again with that carb.
I have a Carter 315S that is on my car now and works fine. I am making some changes this winter and would be willing to sell the carb. PM me if interested.

If the float is properly adjusted then the bowl will only be about 1/2 full. Can he switch the No3 and No4 spark plug wires and then start the engine. After a couple of back fires put the wires back and see if that clears the idle adjustment problem?

Yes, sorry for the confusion guys, I meant the float bowl..... I had a good look last night again at the carb i bought from ebay and the low speed jet was absolutely clogged which is propably the reason for it not idling so I'm gonna try and stick it on today and let you know how it went. Yes, WISEBRI, I will most defenetely be interrested in buying your working carb, thank you very much. Let me know when youre ready and we can talk.

Swap the #3 and #4 plug wires which will cause it to backfire and possibly clear the plugged low speed circuit. Then switch them back to see if it helped.

Ok, so i tried everything and cant get it to run. Im really desperate and feel like buying the replacement unit from fillingstation but it has a hefty price tag.

Keep in mind that if you do buy a replacement carburetor that it may or may not be the correct model number for your car.

Just a back yard guy's two cents but, I rebuilt my '36 carb. and had problems still in it. That is when I removed the plugs to blow it out with compressed air....only I found that those plugs had screen wire behind some of them. The screens were plugged almost shut with very fine sand like particles. Removing and cleaning solved my problem. Hopes this helps.

Thanks to everyone for all the help. i cant say that i got the problem fixed but learned alot through the process which is always a win. I will be buying from joe which runs a 34 as well, i think..... Why would the carb not be the correct one? Does that mean that the carb will work but with problems? I thought 32,33,34,35,36 had the same engines. Does that not mean that the carb should be universal as well? Even if it osnt the right carb, it cant be worse than what i currently have.....

Not that they won't work but almost every year there were changes (improvements) made to the craburetor. The 1934 Standard with the 181 cubic engine had a carburetor more or less designed for that smaller engine.

So, what will hapen if i use the 1935 207's carb on this engine. Will it be o.k. Would i have to change anything? Will it run smokey rich again, please tell me it wont as im sick of the rich carb that is smoking the whole neighberhood full

No, the engines are not the same. 1932 had a 194 cubic inch engine. The 1933-36 Master Models and the 1935-36 Standard Models used a 206 cubic inch engine. A 181 cubic inch engine was used for the 1933-34 Standard Models.

I would think it would work OK. It might take some adjustment. I run a 216 carburetor on my '33 206 and it works great.

Thanks everyone....

Uncle Ed, if you say it may take some adjustment do you refer to the air adjustment screw? My carb is from a 207 which is a long way down to 181.... lets hope and see how it pans out.. again thanks for all the help everyone...