Problems with 72 beetle

[starrider1946]

My vw trike is running good but I have a question about my beetle. I live in Louisiana which it is very hot now. I went to town yesterday to do some errands. I had stopped one place and when I can back out my car wouldn't start. I had just filled it up with gas. I noticed I couldn't see any gas in the filter. First thing I thought was vapor lock. I checked the carb and it did squirt fuel. I checked the points and they fired with the ignition on. So I kept cranking and it finally started. I got to looking at the metal fuel line and it was in the wrong place. It was between the manifold ( dual port ) and the head. I moved it on top of the manifold and put a piece of rubber fuel line around it. Thought I had it fixed. I went to town this morning and after I stopped I looked at the fuel filter and it was about half full. After it sits for a little while the fuel filter gets almost empty. I pulled the top off the carb and the fuel level is right. It is just that all the fuel in the filter disappears. I don't think it is hot enough to evaporate it. Can it be going back to the tank for some reason. Could the fuel pump have anything to do with it. It is a old pump. Thought maybe the pump is loosing pressure or something. It could have been doing this all the time I don't know but I am pretty sure that's why it wouldn't start yesterday. Any ideas.

[sonny8l3]

Hello John, I don't have a clue what might be the problem, I'm mechanically declined. But, If you don't find a solution and you don't mind bringing it to Baton Rouge, I can give you a number for the best VW mechanic in this part of the state. I researched mechanics before I bought my "71 trike and every old VW owner I found for 6 months gave me the same name. He's kept mine running for about 3 years.

Thanks for your time

[DeathBySnuSnu]

It has been a very long time....late 70's.....early 80's.....since I have had a stock or even stockish vw engine.

But by ancient memory.

A fuel filter going uphill from the pump to carb never looks "full"

A big heat soak typically heat expands and the pump valving stops back flow.... so it flows over into the carb throat. Causing a hot engine flood.

A bad pump check valve can let the fuel return back to tank.

A bad pump diaphragm can let the fuel go into the crank case.

[LarryA]

trying to remember back on my 67 beetle.......it had, what I was told, an idle cutoff/ antidiesel solenoid valve on the base of the carb...was supposed to prevent run on after shut down. Is it possible, if you have a similar valve, that it is not closing when the ignition key is turned off and letting fuel leak into the intake?? Just a thought...not real sure...sold the car 46 years ago. good luck on your trouble shooting!

[rhino 2]

trying to remember back on my 67 beetle.......it had, what I was told, an idle cutoff/ antidiesel solenoid valve on the base of the carb...was supposed to prevent run on after shut down. Is it possible, if you have a similar valve, that it is not closing when the ignition key is turned off and letting fuel leak into the intake?? Just a thought...not real sure...sold the car 46 years ago. good luck on your trouble shooting!

My 71 beetle had that solenoid also, When that went bad is wound't let the engine idle , But it would start, just wound't let it idle..

[starrider1946]

My 71 beetle had that solenoid also, When that went bad is wound't let the engine idle , But it would start, just wound't let it idle..

All good ideas. I may put in a new pump. I don 't know how old the one in the car is. I had thought about putting in an electric pump. If I do any suggestions for a good one.

[starrider1946]

Went ahead an ordered a new fuel pump. Went outside this morning and the filter was about half full. I do have the filter before the pump.

[Sidecarbill]

You will have to check the fuel pressure. Almost all of the new pumps put out to much. I think it should be about 2 1/2 pounds or so don't have the manual handy. If the pressure is to high it will cause the problem you're having. It will overwhelm the needle and seat. First thing I would check is look down the carb throat after you shut it off. If fuel is dripping in there thats your problem. I would check the fuel pressure before I did anything else. All parts today are junk. Throwing money at a vw problem sometimes puts you in a worse place than you started at.

[grandpanystrom61]

Not sure of the year, but there was a anti-siphon valve used in VW's, maybe late 60's, but was told it can be a solution to some issues, but I would think that applies if your beetle has one that went bad.

Carb's, fuel, and the pump can drive one nut's. I start at the supply... pump is good and delivering fuel ( as said the pressure of the pump should be checked ) if to much fuel pressure is present than one needs a pressure regulator so that the carb's will get their needed pressure......so you need to know model of carbs so you can look up their fuel pressure rating.

I do hope you the best with it, do you know what type of dual carb's you have on the beetle ?

[starrider1946]

Sorry I should have said it is a single carb dual port motor. Has the 30/31 carb.I don't really have a way to check fuel pressure. I put a new filter on this morning to try that. It cranked right up and I looked at the filter and it was half full with the motor at idle. I let it run for a minute looked back at it and it looks empty. I can't see any gas in it but the motor is still running. I pulled the line to the carb and pulled the the coil wire and turned it over several times and I have plenty of fuel coming out of the pump. I just don't understand why the filter is or looks empty. I always have crazy stuff happen.

Not sure of the year, but there was a anti-siphon valve used in VW's, maybe late 60's, but was told it can be a solution to some issues, but I would think that applies if your beetle has one that went bad.

Carb's, fuel, and the pump can drive one nut's. I start at the supply... pump is good and delivering fuel ( as said the pressure of the pump should be checked ) if to much fuel pressure is present than one needs a pressure regulator so that the carb's will get their needed pressure......so you need to know model of carbs so you can look up their fuel pressure rating.

I do hope you the best with it, do you know what type of dual carb's you have on the beetle ?

[DeathBySnuSnu]

If you are purdy sure you have the pump, lines ect in the back doing what they are supposed to.

Then look at the front.

There is a short rubber hose from tank to metal tube. It can be rotten and sucking air.

The pick up in the tank has a small metal screen on it. It can be plugged.

The gas tank can have some rust in it. Plugging up the small screen on pick up or the metal line through the tunnel.

The vent on the gas cap or on later models filler neck can be plugged up. Caint get gas out without air going in.

Usually problems in the front act like running out of gas. But only at speed. Idle and low cruise. Drive on highway and run out. Stop and crank and crank until carb fills back up and it goes again.

[Sidecarbill]

You're trying to fix something thats not broke. Whether you can see fuel in the filter means nothing. If you pulled the top of the carb off and have gas its not your issue. The car runs and drives down the road then its getting fuel. The hot start problem is not from lack of fuel. Its possible I misinterpreted something if so my apologies. To get the car started do you have to pump the pedal or hold it to the floor. When it starts does black smoke come out?

[grandpanystrom61]

Well some like a single carb over dual carbs. I run dual carbs on my trike, but at times they seem like more trouble than I wanted, LOL

Now a fuel pressure gauge can be borrowed from most part houses now. At least on the west cost area they started a tool loan program from the local auto stores.

No way am I a specialist or a carb mechanic, I just have always played with them and kept my vehicles running.

I have only ran an electrical fuel pump on this trike, so do not know how a manual pump fuel flow would look in the filter, but it would be spurts of fuel I would think, but one would think as the pump delivers more fuel the filter would fill up as the carb can only use so much fuel at one time, if the bowl if full and at idle, I can run for over 10 minutes at idle before I notice a idle rpm issue...........just means it wants more fuel setting in the carb bowls.

Losing lot's of fuel, not sure were it is going, it can drain into engine oil, so pull the dipstick and smell the oil, if it stinks like fuel to much, drain and change the oil, but it is best if you can resolve the fuel issue first, other wise you might have to do a few oil changes, okay I had to do it that way.

www.thesamba.com is a VW site, old school VW owners, off roader's and restorer's offer lots of help and you can find a lot of info from previous members issues. I have found some help on issues over there, just wish I knew more about your carb to help you more.

[grandpanystrom61]

I guess I need to clean the keyboard if I want to stop double posting, I hope everyone has a great day.