A couple problems...need advice.

[47heaven]

After having the gas tank recoated, a new fuel line and fuel pump installed and the carburator serviced, it still seems to flood with gasoline and run down the sides after I turn the engine off. What could be causing this? I thought I fixed that problem with a new line, fuel pump and fuel filter, and it still does it most every time I turn the engine off. It doesn't do it when the car is running.

Could a faulty/broken heat riser be the cause of a vacumn leak? I drove the car to the mechanic after trying to tinker around with what could be causing the leak and causing the engine to miss at times. He said that the heat riser could be the cause and turned it somewhat. That seemed to help a little, but I still get an occasional miss at idle...sounds like a quick whoooosh sound that makes the engine seem like it's missing. Has anyone had something similar like this happen to them? Could this be tied in with the carburator problem as well?

[Don Coatney]

Best to return the car to the mechanic and have him fix it. I (or others) may be able to tell you what is wrong for free. But if I (or others) do so and you then tell your mechanic what was told to you and he does so then charges you to do the recommended work I am a bit uncomfortable with that.

[bob_amos]

Being a professional mechanic myself I can tell you that it is always best to drop your car off at the shop, tell him your troubles and let him determine the fault. We don't really like having a customer tell us what he thinks is wrong. I have had customers tell me exactly what they wanted done and did so for them, only to find that it did not repair the car. And then... they want me to now do the work for free because what I did was not the correct thing to be doing. SO.. if you tell the mechanic what to do be ready for it to not repair the car. And to cost you more in the end.

[greg g]

Usually gas coming out of the carb is caused by two things, an improperly set float level, causing the needle not to seat and shut off the flow of fuel, or some debris in the needle/seat area preventing it from closing. Some of the sealing goop may have broken loos and lodged in there.

[1just4don]

Just a wild stab, but here goes. Is the fuel line from the pump up to the carb anywhere near hot metal?? Could the fuel inline be superheating and sorta boiling, like a vapor lock but different?? Like the pump has it locked up and the extra pressure built up in the line cant go back past pump,,,so HAS to overcome the float and needle and overfill the carb???

Might try insulating the line past the motor,manifold, or any other parts that are hot and see if that changes anything. If so, ya got it,,,if not,,,keep looking,,,but as has been said needle and float are best place to start,plus any debris that floats up in the line!. Is the float completely empty of fuel,,,leaky floats sink and overfill carbs.

[Lou Earle]

Think about it - The only way a carb can Overflow and therefore leak-assuming no crack somewhere- (and if cracked would leak all the time-so that is out as the problem)is to much fuel in the bowl and there are acouple or 3 ways that can happen

1- float set so it does not shut off fuel flow that is one purpose of the float - to close/open the needle valve to measure the fuel to the carb.

2-debris in the needle valve.

3 fuel pump to powerful and "forces" fuel in- I have never seen this happen.

4 the float has a hole in it and is now full or partly full of gas it does not set right and rise and fall correctly

5- BE SURE THE NEEDLE OF THE NEEDLE VALVE IS IN THE CARB

Several times i have had your problem only to find the needle was missing! It is very easy to drop out and loose.

I think your problem is in the carb- carry the service manual to him and leave it for repair.

Want to see for sure if it is carb problem Get a rebuilt one from Asche ( about 80 bucks) and put it on. I believe every old car owner should always have spare carb and as tune up knit around anyway.

Good Luck

Lou

[Lou Earle]

All the heat riser does is allow hot exhaust to pass over the bottom of the intake manifold no exhaust goes into the intake that I know of.

On 2 of my cars I found bad hose to the wiper was the cause of vacuum leaks . Remove your hose from the vacuum line and replace it with a short piece with a bolt screwed into one end as a plug. that should tell the tale about that.

Also back to the carb again- poor gasket or poor fit of carb on manifold due to warpage, not cleaning carb base and manifold face, all can cause air leaks.

If you run your car at idle and can close the air/fuel mixture screw shut you have a vacuum leak.Also many time what u think is a vacuum leak is not. It Will act like a vacuum leak if the Idle mixture screw is set wrong

you can check this yourself by turning the idle mix screw clockwise until closed - but not hard just snug; then, open it 1 and 1/2 turns and start car. and adjust it with car running. Turn counterclockwise until car is at max running/ idle speed then turn clockwise until starts to slow down then counterclockwise to just where it speeds up again - it is set.

I am betting the carb is not on the manifold right. A lot of people use #2 sealant or other sealers to compensate for gaskets or poor cleaning. Check your manifold to carb mating and be sure there is a gasket there.

2 cars I got had no gasket but had form a gasket or something (rtv?) trying to replace the gasket - that was a disaster-

Any way hope this helps.

And by the way If I take my older cars to a shop for work I carry them the shop manual( do not leave home without one - EVEN if you stayed at a Holiday Inn). I do tell them what I think is wrong- Why? Because many mechanics are not knowledgeable about older cars. Think about it - If a person started dong mechanical work at 20 years old and worked on our 50 + year old cars he would be at least 70.

Only a few of them still standing and thank God they are!!.

Lou

[Lou Earle]

Don's point is well taken, but I do share my limited knowledge and experience because many mechanics do not know about these older cars and we do. It can help him and you

How You ? Well, if you find the carb float is wrong or he put it on with rtv or something other than gasket with small amount of sealer or needle valve is missing you will need to decide if you want to have him do any other work. After all, he implied by taking your job he knew what he was doing. But he might not that will be your call.

I am presuming you have a shop manual- If not get one- best 25 bucks u will ever spend

Lou

[knighthawk]

Does it leak fuel when it's hot or cold ? Where excactly is it leaking ? could be a cracked bowl, wouldn't show up durng a rebuild , unless looking for it . Engine miss : spray some soap water around all the lines and fittings, and listen for a change in the engine , and / or close off the vacumm to different lines. Heat risor, only directs more heat up and under the carb. If this is in question, carefully unhook the spring, and let it fall open .....good luck

[bob westphal]

All of the suggestion made a very good. However, there is one thing that hasn't been addressed. That is carb boil, which I believe is what your mechanic suspects. The chances of this problem is remote but is quite easy to see the symptoms. It can be caused by a partially plugged exhaust manifold, defective heat riser, or defective header pipe. Look at the area directly under the carb. Signs of higher than normal heat in this area such as the paint is burned and peeling, etc. High under hood temps can also cause this to a small extent. One fix , other than repair ing the plugged sysytem is to install thick spacers between the carb and manifold. I personally think that you have carb flooding caused by any or all of the things already mentioned and not carb boil.

[1just4don]

looking for a vacum leak is very easy on these girls. Squirt any possible area of suspect with carb cleaner while running.(idle is fine) Will definately get a different RPM and sound when you hit the offending part. Will sound like a racehorse on steroids for a second. It cleans off a little grime at same time,course YOURS are spotless,,,mine are gunky!! Try all different angles, ends of hoses,fittings etc.. Just a little goes a long way,,,no LONG squirts necessary. A little dab will do ya!!!

[47heaven]

Hey guys...thanks for your advice and troubleshooting. I'm going to print all of it out and try to figure out what is happening this weekend, as well as keep it for reference.

There is a 1/2 inch spacer between the manifold and carb. It's really hard to see where the gas is coming out because the carb is very clean on the outside, as well as the inside. It only does this when the engine is hot and has been turned off. Sometimes I've noticed that when it's flooding that the fuel filter is full of gas and other times it's not. Wondering if it could be a back up or something.

There is no heat shield between the manifold and the fuel pump and the line passes about passes a few inches in front of the manifold on it's way from the pump and filter. It is a steel line.

As far as where there could be a vacumn leak....the old connection to the wipers is plugged with a rubber cap. The vacumn to the distributor is tight at the carb, but will have to check it at the distributor. This same line looks a little bent up, so it may be possible that it has a crack? Maybe it should be replaced. Well see.

[knighthawk]

If you think the heat on the fuel line may be the cause, just try putting some wooden snappy clothes pins on the fuel line. ( dissipates the heat ! ) in the area ny the manifold. and up to the carb. Betcha it works ! If it does help, then you can make a heat shield for it .

[Guest Nile Limbaugh]

Seems to me that the level in the fuel filter should remain constant. If it isn't it could be exhaust heat which is boiling the fuel out of the filter bowl, into the float chamber and out of the carb:confused: . Comments, guys?

[47heaven]

I went to a lead sled car show today, even though my car is stock, and ran into a guy that has a 1949 Plymouth business coupe that he customized. Turns out that he's a mechanic and knows a lot about early Plymouths. He checked my car out and told me that the reason that I may be having the overflow is because my fuel filter is up too high and needs to be lower than the carburator. Second, it turns out that I have an exhaust leak, and not the vacumn leak that I first thought. Now we have to troubleshoot from where the exhaust leak is coming from...which could be numerous things.

[Guest Nile Limbaugh]

Even if the filter is higher than the carb it seems to me that the float should cut off the flow anyway, if it's doing the job.

[Normspeed]

Here's another angle on the flooding. When it's doing that, go and remove the fuel filler cap. Does it come off with a big whoosh of air? Fuel tanks can build up their own pressure due to ambient temp, road heat, etc. and if the tank is not venting properly they can pressurize and push fuel thru the carb. My P24 was doing that (wrong fuel filler cap). Also when rebuilding the carb, there is a little inverted horseshoe clip that holds the float pivot in place. If that's not in there the inlet needle will tend to leak under pressure.