1972 VW Beetle dies on hills

I have a '72 standard beetle with the 1600 dual port engine and the stock original carb. The Carb has been rebuilt, and my problem persisted even after that. The issue is that when I am coming down a steep hill and I have to stop at the bottom, the engine will die. It goes like this: In 1st gear, coming down the steep driveway of my house, i come down at 10-15 mph, using the engine and some brakes to slow. Near the street at the bottom, I push in the clutch and brake to a stop. As, or even a moment before I stop moving, the engine quits. It then starts right back up again and idles and runs as if nothing was wrong. It runs perfectly other than this issue. I can get it to keep running if I put it in neutral, keep my foot on the gas and use my left foot to brake, but it is inconvenient. I was thinking carb float level? If it is too low, could the angle of my driveway, plus the fact that the throttle is closed, plus the added force of the brakes make the fuel in the bowl move foreword enough to momentarily starve the engine of fuel?
This was the only theory I could come up with, and I may be barking up the wrong tree but any help would be appreciated.

You’re on the right track, I bet.
I’d check fuel delivery first too. Make sure your fuel filter is okay. It still has a mecanical pump? Some people have added a fuel filter under the tank and a next owner may have just replaced the one then engine compartment without even knowing about the additional one under the tank. It is worth checking.
Junk does collect in the tank. They come out easy so it could be worth taking it out and shaking the junk out.
It could be carb related as well, of course. Maybe the float is not doing its job. You could take it off and clean it out.
When was the last time you did a full tune up?
Those are just some of the possible causes. There are many.

Btw, a better place to search for answers specifically on ACVWs is www.thesamba.com. That’s all they talk about and some of these guys know those vehicles inside out.

This could also be related to carburetor adjustment or an intake air leak since this is a dual port engine.
There’s a procedure for adjustment that MUST be followed and this cannot be done unless it’s known that the intake boots are not leaking, ignition timing is correct, etc, etc.

Info on the carb overhaul might help also. Was the carburetor body soaked in solvent, washed out, and then blown out with compressed air?
Did you remove the brass, C-shaped accelerator pump discharge tube from the body when overhauled?
(This is critical because of a tiny ball inside that circuit that may get lost and can cause idle problems if missing; all depending.)

@nickp1023 Does it do this only when cold (first thing in the morning) or at all times, regardless? Choke issue?

I guess it could be frozen riser tubes as well but usually a car won’t immediately start back up.

I wonder if a weak fuel pump could be causing the problem. The engine is in the back of your car and the gas tank is in the front. When you are going downhill, the pump has to work harder by pumping the gasoline uphill to the engine.

He didn’t mention whether it was changed, but a 72 has a mechanical pump on the engine.

The carb float is a good possibility. Some are adjustable, some you have to get inside the carb and bend the arm on the float.

I expect from the above comments this classic car will soon be running good as new. My neighbor has one of these cars, I see her driving about town with a big smile on both the car and driver. It needs some rusted bodywork & other restoration and a good paint job. So I asked her if she wanted to sell it. "Never! This is my baby! " she said! … lol

lol - yeah, tooling around town with a bug is an addiction. There’s nothing like that aircooled “FFFfffweeeem” sound.
People always make a point of stopping and saying “Boy, I had a bug when I was a kid…”.

“Boy, I had a bug when I was a kid…”.
@Remco–The VW Beetle was probably the most popular car on college and university campuses back in the early 1960s. The more affluent students (by affluent, I mean a student that could afford a car) owned VWs and many of the professors also had VWs. VWs back then had a low depreciation rate and when I was ready to buy my first car, a used VW was out of the question. Even when I went back to graduate school for the second time in the early 1970s, the VW Beetle was still a popular choice. I presently live in a city with a mid-sized state university and the VW dealer is no longer in business. Somehow, VW couldn’t sustain the popularity of the original VW Beetles.

Check that the float is perfectly centered in the float bowl and not worn on its hinge pin so it can move off center and jam or stick on the edge of the float chamber, cutting off fuel under the conditions you describe…

“Boy, I had a bug when I was a kid…”

I bought a used 64 Sea Blue Bug and drove it for years.

My next car was a brand new 71 Clementine Orange VW Super Beetle (1st year of Super Beetle & also dual-port) with a steel sliding sunroof. The car, brand new cost me $2350.00 ! I drove that one until the wheels fell off.
I worked at Volkswagen at that time.

CSA

You just proved my point: everyone has a vw story. :slight_smile:

VW has lost their way and has been trying hard to forget about their blue collar volk beginnings.
There’s a huge following and the car hasn’t been supported by vw in decades. Naturally, there are a lot of small businesses that have picked up that slack, making parts.
Wouldn’t you know that VWoA, the same company that quickly distanced themselves from that quirky car, has been very quick to bulley and arbitrarily sue people that use their logo while making a profit?

Now they want to go back to their roots in commercials by showing a mid 60 bug to their modern interpretation.
They’ve alienated most acvw hobbyists. It isn’t the same company anymore.

I has a 71 Bus which was was first year of the twin port head and it came with no fuel filter at all. I didn’t find that out until my first visit back to the dealer at 3000 miles because it wasn’t running right and they charged me $99 to clean the carb and then wanted $50 to install a super duper fuel filter. I walked to the auto parts store two doors away and bought a $1.50 filter and installed it in the dealers parking lot. That was the second last time I went to the dealer, The last time was at 23,850 miles when they had to rebuild the engine under the 24,000 warranty. I liked the bus, hated the air cooled engine.

Check the ignition timing and manifold vacuum.

More on VW bugs … my favorite TV channel is called “ME TV”. It’s sort of embarrassing to admit, because this channel advertises basically nothing but catheter supplies (I think it is best not to ask what this is for), Medicare supplement health insurance plans, high risk life insurance plans, adult diapers, and those little electric carts older people tool around in and scare everyone on the sidewalk. It’s embarrassing, but it’s true!

Anyway, I watched an old re-run from the late early 70’s the other night on MeTV, a show called “The Odd Couple”, and the Manhattan street scenes had all cars from that era of course. And most of those cars were pretty ugly. With a few exceptions, the early 70’s were not a good year for auto styling. For example the early 70’s Ford Galaxy. Functional, but very homely. But one of the cars in the street scene parked by the side of the road was a red VW Beetle, and it looked great. Very avante guarde, modern looking. A car you want to like, just on appearance. Even now.

This reminds me of old stories where the oil sump or fuel pump stop operating at certain angles on hills because of the way something is designed or installed, so you might want to check to see if you’re losing fuel pressure or oil pressure when the vehicle is at certain angles.