TheSamba.com :: View topic - '57 Oval Fuel Reserve Switch and Stalling help needed!!!

Fri May 30, 2008 5:07 am

nichelob wrote: Thanks for all of your help. I am going to rebuild the carb this weekend and troubleshoot from there. Maybe there is gunk in my carb.

I will update you on Monday.

This is killing me. There is nothing worse than having a perfectly good '57 Oval sitting in your garage that wants to run but you can't figure it out; unless of course, it's a Splitty...

Cheers!

Try using a different cap on your tank. If it lets no air through into the tank, then the fuel pump will not be able to pump out more gas. That could explain why it will restart after sitting for a while

Fri May 30, 2008 7:00 am

I tried that last week and there was no suckking noise, so I believe it is not vapor lock.

Will try to rebuild the carb this weekend. Maybe be gunk in the carb that is blocking the lowing of fuel or the proper operation of it.

I am boggled as to what it can be though.

Fri May 30, 2008 8:15 am

Drive it till it stalls, then immediately shut off the key and take the top of the carb off. You can do it while it is still on the intake. See if there is gas in the bowl.

If not, you have a fuel supply problem. I'd suggest starting at the tank, check the screen (not sure if you did that already, didn't read the whole thread), shoot some carb cleaner though the metal chassis line and then blow it out with compressed air.

Check your fuel pump. When they fail they can get "weak" work OK for a while, then slow down, or fail to sustain a highway run when doing fine around town.

If the carb bowl is full, it might be a carb gunk problem, or ignition issue. If you can crank it and it doesn't start, pull a plug out. Wet and/or smells like gas, probably an ignition problem. Dray and odor free, probably a carb problem.

Keep us posted!!

Fri May 30, 2008 10:30 am

Yes one of the biggest VW gremlin problems out there, if not the biggest. Happens to most of us at one point or another, you're not anywhere alone on this one.

The diagnoses so far are on a few right tracks to evaluate, and either way or completely you get a complete tuneup out of this effort. Its sort of a flowchart approach to figuring this out. Just not enough data yet though to pinpoint, sort of seems like stabbing here and there so far.

Its either fuel or ignition as its been said. I suspect fuel supply first since if it runs well or sounds like it runs well when its running its not likely ignition.

First check the silly stupid stuff, like inside the tank, look inside, for anything floating around on the bottom. More times than not what happens is something small might obstruct the fuel flow getting into the petcock/fuel valve. Could just be 50 years of gunk, since I know more guys that have pulled out more wacky things like gas additive spout paper/foil seals and other such junk that float around in tank and then they eventually become a problem, then they float out of the way for awhile, and back, so thats the silly obvious thing.

Next you could/should rebuild/clean out the petcock valve too anyway. I agree with John also that the fuel pump could be the culprit, there are a number of ways to test fuel flow out of it and into the carb by disconnecting the fuel line from the carb and turning over the engine (just empty the gas into a glass jar though for safety). You can also check fuel flow into the fuel pump by just disconnecting it and see what gravity delivers. Also double check underneath for any forgotten old inline fuel filters, replace them anyways. If you just swap the fuel pump out with a good rebuilt that will tell you automatically its not the fuel pump, if you have that option, and luckily they are relatively inexpensive (go to vintagewerks.com if you want a good one fyi).

But, if you have decent noticeable gas flowing in and out of the current fuel pump , then yes go to the carb, I suspect the carb more than anything. You just got the car, so its worth the rebuild just for a good clean, and just cleaning out the fuel bowl may solve the problem, one or more of the jets might be getting clogged etc, the needle valve might be leaking as well and could be a cause of the hard restart (will flood your engine), but I don't suspect it as the only culprit here. Old stuff just needs to be gone over good here, you may cut off 6 other near future problems in the future.

Once you rebuild the carb from the standard kit and you know its squeaky clean (inside the galleries as well), then run the car and see how it behaves. This way you have at least gone over the entire fuel chain. So if then its not fuel, then it is narrowed down to ignition. The other culprits there can be a number of things to try, and cut outs on a yet to fully warm up engine could be as simple as a bad condenser. I doubt its a bad or weakening coil but you should check its spark color and it should be bright white. A coil will warm up considerably and do flaky things when its weakening, so it could be the coil as well. You should replace the spark plug wires too but doubt thats the problem. Check the condition of the points as well and reset them if you haven't already. I'm not a big fan of mechanical distributors but they do work.

After that, you got me. Its not vapor lock though thats nearly certain. I think you just need to sign yourself up for a general going over and not rush it too much, then you'll be more confident anyways taking it on longer trips.

The carb also sounds like it leaking from the throttle shaft, very common, gums up alot the area and at some point you should have it rebushed (at Rimco for example), or perhaps even just buy a rebuilt carb where the throttle shaft is nice and tight as possible. You can diagnose and fix the problem on a budget yes, and its good way to understand your car better, each one it seems has its own personality. Good luck!

Gary

Fri May 30, 2008 10:38 am

Make sure your float is OK. I had a similiar problem earlier this year with my 36hp.

Fri May 30, 2008 11:22 am

One more thing, before you rebuild the carb make sure the body is not warped by putting the upper and lower half against a straight surface, like a pane of glass to check for flatness. Also check that the throttle shaft is not worn or out of round.

Sun Jun 01, 2008 6:21 pm

Okay.....

So I rebuilt the carb, started the Bug and adjusted the idle. It idles great. I drove it around my complex about twice (picture a big circle about the size of a baseball field), and braked hard to see if it would stall. It drove strong and then, after the second circle it started to sputter again. Finally I got it to my garage before it totally konked and popped the engine lid.

Gas once again was leaking out of the carb and down on my intake manifold and onto my distributor. It is coming from the two rear screws that hold the top and bottom housing together - right above the bowl. I am definately getting fuel, so that is not an issue. I waited about 10 minutes and it was a hard start, but it started. I had to floor the pedal and it started after trying to turn for about 10 seconds. It idled great!!! No konking out, no gas leaking. It just seems to stall when I begin driving. Not sure why... :roll:

In the past two weeks - I completely rebuilt and cleaned the carb, rebuilt the fuel pump and changed the oil. The timing is right and I have adjusted the valves.

I am completely at a loss.

There is gas in the bowl and the float is floating. What could it be? Anybody had this happen? The engine is strong, but as soon as I start to drive it, the damn thing wants to konk out on me after about 1 and a half minutes.

Oh yeah, when the car finally konked, I opened the lid and was able to pull the dip-stick out. It was hot, but was handle-able.

Please help me!!!! I am about to drive this '57 off a bridge....(j/k)

Sun Jun 01, 2008 10:34 pm

Got another carby to try?

Mon Jun 02, 2008 5:36 am

No other carbs. What does this problem sound like it is?

Mon Jun 02, 2008 5:44 am

Another carb would tell if it's carb problems which it sounds like. Needle and seat all right? Sounds like the cutting out is flooding somehow and hard to start till it gets the excess fuel blown out by turning over. My guess would be needle and seat, it runs OK till the bowl fills up then overflows and floods.

Mon Jun 02, 2008 5:48 am

Sounds like the top of the bowl is warped. When you drive and the fuel starts sloshing around, and breaches the split between the top and the body of the carb. It then pours down into the throat and causes the sputtering. Once you start the car again it's stable, with no movement, so no fuel pours into the throat so it idles great, then you start to move, the fuel sloshes around and causes the sputtering again. I would get a new carb from Mark, he rebuilds them, checks for warped bodys, throttle shaft leakage, beadblasts them, top notch work for a reasonable price. He also rebuilds carbs for Formula Vee racers so he really knows his stuff...

http://www.thesamba.com/vw/classifieds/detail.php?id=221709

After I got my carb from him my mileage went up to 32 mpg from 18 so I don't hesitate in recommending him. I'd be real careful trying to order a "rebuilt" carb from somebody else, it might have the same problem as yours.

Mon Jun 02, 2008 6:25 am

So after everything I have described, you all think this is strictly a carb issue? It makes sense if it overflows with fuel I guess.

Just want to say thanks again for everyone's help particularly Ninamashr. You've been like my personal Beetle mechanic.

Cheers to all!

Mon Jun 02, 2008 6:25 am

Ninamashr wrote: Sounds like the top of the bowl is warped. When you drive and the fuel starts sloshing around, and breaches the split between the top and the body of the carb. It then pours down into the throat and causes the sputtering. Once you start the car again it's stable, with no movement, so no fuel pours into the throat so it idles great, then you start to move, the fuel sloshes around and causes the sputtering again. I would get a new carb from Mark, he rebuilds them, checks for warped bodys, throttle shaft leakage, beadblasts them, top notch work for a reasonable price. He also rebuilds carbs for Formula Vee racers so he really knows his stuff...

http://www.thesamba.com/vw/classifieds/detail.php?id=221709

After I got my carb from him my mileage went up to 32 mpg from 18 so I don't hesitate in recommending him. I'd be real careful trying to order a "rebuilt" carb from somebody else, it might have the same problem as yours.

Sounds plausible, but I also wonder if it is being flooded. If there is a problem with the needle valve, float, float height, hinge, etc. Still should not be leaking between the halves however. I'd like to take the top off right after it stalls and see how much fuel is in the bowl...

Mon Jun 02, 2008 6:27 am

Sounds like was Ninamashr said that the bowl is warped. Is that a common issue?

Mon Jun 02, 2008 6:45 am

I wouldn't say it's a common problem, but, that is what happened to my carb. What John says also has validity. If the float valve is not seating properly then fuel would just continue to pour into the float chamber, and subsequently out the split too. I am assuming that when you rebuilt your carb you replaced the float valve with a new one, so it would be wise to re-check that the float setting is correct, also make sure the float itself is not leaking in any way too. Shake it when you take the top off to see if it has fuel inside.

Mon Jun 02, 2008 6:54 am

Ninamashr wrote: I wouldn't say it's a common problem, but, that is what happened to my carb. What John says also has validity. If the float valve is not seating properly then fuel would just continue to pour into the float chamber, and subsequently out the split too. I am assuming that when you rebuilt your carb you replaced the float valve with a new one, so it would be wise to re-check that the float setting is correct, also make sure the float itself is not leaking in any way too. Shake it when you take the top off to see if it has fuel inside.

The pump will actually pressurize the bowl if the valve/float is not shutting off, forcing fuel out of the tiniest gap.

Mon Jun 02, 2008 6:58 am

I did not replace the float, just the standard rebuild kit; however, when I open the casing back up, the float was not stuck and had not cracks, holes, etc. No fuel was inside the float and everything checked out okay, including the friction between the float and the pin that hold it in the casing.

Talk about befuddlement!!! Argh!!! :x

So you all think I should just invest in a new carb? (Mark's to be specific)

Mon Jun 02, 2008 7:01 am

Yeah, toss a new carb on there and see if that fixes it. Have your rebuilt in the meantime. 28 carbs aren't that hard to find....

Mon Jun 02, 2008 7:04 am

Will do. I'll keep you posted.

It's killing me to not be able to cruise this puppy around town...

Mon Jun 02, 2008 7:29 am

Yeah, that sounds like a plan. New carb and keep the old one for parts, one tip to remember NEVER throw anything away. :wink: