Jay Salser Posts

1967 Volkswagen Beetle Fuel Pressure

Another fantastic and well articulated article from Jay Salser. Our timing lights are pointed in your direction. Thank you for all you do here at 1967beetle.com.

I commonly hear the words—“I had a vapor lock!”

We mostly think of vapor in conjunction with heat. So a BIG question arises when the “vapor lock” occurs under cool circumstances. This renders such a diagnosis suspect.

It is very easy to blame a poorly functioning air-cooled engine on a “vapor lock”. When someone calls to ask what can be done to cure a “vapor lock”, I ask lots of questions.

I want to hear how the car-engine acted. I want to hear about the circumstances that led to the problem. I want to hear about the ambient temperature.

My mind follows the Fuel System from the Tank to the Fuel Pump. And I literally ask the caller questions during my mental perusing of the Fuel System. It’s like a movie playing through my brain as I listen and ask questions.

Did the engine just quit?

Did the engine buck, then finally stall?

Usually people try things like pouring water over the Fuel Lines or over the Fuel Pump.

Or, maybe the caller has changed the Fuel Filter.

In any case usually no firm diagnosis is reached and the next time it happens, the same scenario plays out.

One person reported that his car stalled at the roadside. A passing motorist stopped to give aid. He produced a bottle of water and poured it over the Fuel Pump. Soon, the engine started and the driver resumed his journey homeward. The assumption—the Fuel Pump had suffered a “vapor lock”—even though the weather wasn’t even hot.

Recently, Frank Salvitti talked to me about the “vapor lock” which temporarily put his car out of commission. He had driven a few miles, parked his Beetle and gone into the store to make his purchases. When he came out—the car would not start. He said that he could not see any fuel in the Fuel Filter (mounted, still, in the engine compartment). Eventually, after the engine had cooled, he surmised, the car started and he drove home.

Here’s what I asked Frank to do. I asked him to get a Fuel Pressure Gauge to connect between the Fuel Pump and the Carburetor. In a few days, he reported Fuel Pressure in excess of 5 PSI. This is far too much pressure.

The Float Valve (commonly called the Needle Valve) in the top of the Carburetor cannot withstand such High Pressure. Gasoline forces its way into the Bowl and begins to overflow down the throat of the Carburetor. When this happens, not enough air can mix with the un-atomized gasoline and the engine is choking to death on raw fuel. It either stalls or won’t restart after having been turned off.

Until all of that raw gas has dispersed and evaporated.

Think of the Bowl of the Carburetor as a toilet tank. If we hold the float down, water continues to fill the tank until it finally overflows. We have generated “excessive pressure” on the tank float—overpowering the cut-off mechanism.

Sometimes the Pressure is so great that gasoline can be seen percolating in the filter (if it is connected between the Pump and the Carb). With the Air Breather removed, raw gas sometimes can be seen over-flowing down the throat of the Carburetor. This especially can be seen if the car has been parked nose-uphill.

First, let’s review how the Fuel Pump operates through the following photographs.

The 1967 Beetle Fuel System

fuelsystemheadlinerphoto-67bug-gasstation-1
The Fuel System of an air-cooled Volkswagen is not a complicated System.

But, there are some Fuel Issues which continue to plague the VW Community—some of them easily resolved with a little bit of thinking and work. These are things which most of us can do ourselves.

First, rather than running to all of the forums on the subject, it’s time to sit down to consider how the Fuel System of our Beetles works.

CAUTION: When working with Gasoline—ALWAYS work outdoors and away from any source of flame or spark!

The Fuel Tank:

Complaints about Gasoline Fumes are common. Two things usually contribute to Gasoline Odor in the Trunk. This Odor often penetrates to the Cabin area.

Let’s talk about the Tank Filler Neck. Note that there is a tiny Tube coming off the Neck
pointing towards the left side of the car. By removing the Gas Cap and looking into the Filler Neck, we can see the Tube protruding into the inside of the Filler Neck. Where it protrudes, it is slightly pinched. This is to limit the amount of liquid gasoline which can escape through the Tube. A tiny Rubber Vapor Hose (N203531—ID-2.0 mm/OD-3.5 mm) is pushed onto the tube where it exits the Filler Neck. It needs no clamp since it fits tightly and there is no pressure upon it. (Note: Vapor Hose also may be marketed as Vacuum Hose.)

The Vapor Hose loops back towards the driver, then back again to the front of the car where it is pushed through an opening and allowed to dangle several inches beneath the car. Thus, any Gasoline Vapors will exit beneath the car and will not escape through the Trunk area and into the Cabin. If the Vapor Hose is missing or improperly routed—Gasoline Vapors will permeate the Trunk area and pass into the Cabin. Be sure that the Hose is present and routed through the hole to beneath the car. 2 Hose Clips (111-201-261) keep the Vapor Hose stabilized on the Cowling Loop.

If the Tank Filler Neck Tube becomes plugged, gasoline will not flow properly from the Tank Outlet. Also, make certain that the Vapor Hose is not pinched or plugged.

’67 Beetle Fuel Hose Clamp Tool

’67 Volkswagen Beetle — Fuel filters
When talking about working on the Fuel System of our Beetles, one of the greatest concerns we have is Fuel Spillage.

Gasoline is a wonderful “invention” but one which we should respect because of its evaporative and, thus, flammable qualities. We must use great care when working with gasoline. My number one rule is to work with gasoline outdoors so that gas vapors cannot accumulate

I frequently am asked by fellow Volkswagen enthusiasts what to do about gasoline spillage. This is a valid concern. When changing the fuel hoses, there always is the possibility for some gasoline to be spilled.

THERE IS A BETTER WAY!

While talking with my good 1967 Beetle friend, Frank Salvitti, of Long Island, New York, this past weekend, the subject of fuel spillage came up.

Says Frank—“Oh…that’s no problem! I use Line Clamp Pliers.” Now, Frank is a seasoned mechanic and knows things that a lot of us DIY-ers don’t. I asked Frank to explain his process and he told me that he would send some photos to illustrate his tool of choice.

Over the years, I have seen screws inserted into the ends of hoses, pieces of whittled wood, and other variations, in order to avoid the loss of gasoline while the person is working to change fuel hoses. But it takes time to insert something into the hose. In the meantime, the gasoline is draining. I laugh now, but I recall the many times I was beneath a VW, working on a fuel hose, and had the fuel to drain right onto my face or clothing. Not much way to avoid it if you are working with the fuel hose over head!

Frank emphasized the simplicity of the Line Clamp Tool and how to use it. The beauty is that if anything at all spills, it will be a couple of drops which remain at the end of the hose after it has been clamped. A paper towel can be placed there when the hose is disconnected and will take care of such a small amount.

The Clamp is applied appropriately—THEN—the fuel hose is disconnected.

30 PICT 1 Main Jet Configuration

NOS Solex 30 Pict-1 Carburettor

A Volkswagen friend in England recently e-messaged me about a situation with his carburetor. His is a 28 Pict-1 but the situation is identical to that of the 30 Pict-1 carburetor.

The proposed problem deals with the Main Jet of the carburetor.

When my friend experienced some carb problems, he began to search the Internet for helps. He discovered a video and watched it and followed the instructions.

When the video came to the Main Jet installation, the mechanic pointedly explained that the hole in the Main Jet Carrier Bolt should align with the hole in the bowl of the carburetor.

My friend attempted to get the holes to align but was unable to do so. Now, he thought that he had a problem. He asked me if he should not tighten the Carrier Bolt, but leave it a little loose so that the holes would align.

carburetormainjetseries-5a

By not tightening the Main Jet Carrier Bolt, gasoline will seep to the outside of the carburetor, resulting in the problem of raw gasoline in the engine compartment—a problem which none of us wants.

In the Carburetors mentioned above, the brass Main Jet Carrier Bolt also serves as the Plug for the bottom of the Carburetor Bowl. (Later carburetors have a simple steel or brass Bowl Plug. The Main Jet was separated from the Carrier Bolt and moved to a new location but has the same function).

With the Main Jet Carrier Bolt in hand, note that the area which has the holes is recessed—of a smaller diameter than the rest of the Bolt. There are three holes drilled on opposite sides of one another. This is so that gasoline can pass through the hole in the bottom of the Carburetor Bowl and enter the recessed area where the Main Jet Carrier Bolt resides. With the Main Jet Carrier Bolt installed, gasoline in the Bowl can freely circulate around the Carrier Bolt and enter the 3 drillings in order to pass to the Main Jet.

Undercoating Vintage Volkswagens

Undercoating Vintage Volkswagens

Digging in the archives here at 1967beetle.com, we wanted to put this article in the spotlight once again.

Foreword: Rather than to address “undercoating” as a general topic of discussion, I’ve tried to keep the focus upon undercoating as it related to Volkswagens through 1979 and as it relates, now, to the vintage Volkswagen hobby.

Undercoating has around for years and years in the world of vintage Volkswagens.

The theory behind undercoatings is that a barrier could be created to prevent the infiltration of moisture. Undercoatings themselves had no rust-inhibitive qualities. They simply have been intended as a barrier.

VW dealerships sold the service to new car buyers as a preventative measure to guard against rust. It was a money-making operation and dealers loved it. Especially was it offered in the colder climate States and especially where salt was used on icy roadways.

Recently, I spoke with a former VW trained specialist. He described the undercoating procedure as he observed it. He said that the dealership where he worked had one bay with a lift, “in a dark corner”, where the “nasty” undercoating took place. He told me that it was part of a money-making effort by dealerships in the make-ready department. Undercoating was applied using a hose and gun working from a 30 gallon barrel of material.

I have had my doubts over the years about its effectiveness in sealing the undersides of a vehicle as a moisture barrier. Here’s why. I was in the painting industry for almost 30 years. If there is a coating, I likely have seen it or read about it. In my experience, despite all claims to the contrary, coatings will fail. There is no “eternal” coating. I’ve heard claims that “you’ll never have to paint again”. Why can’t this be true?

Undercoating Vintage Volkswagens

It can’t be true because of expansion-and-contraction problems. When the base material—wood, metal, plastic—expands or contracts, the coating is going to suffer, eventually. Some coatings are better suited than others. But the fact of the matter is that coatings fail.

Metals, especially, are given to fluctuations from heat and cold. They will expand and contract more, and more quickly, reacting to weather and usage conditions.

What’s another problem? It’s the fact that the underside of a vehicle is not a continuous sheet of metal. Not at all. The undersides of vehicles are composed of pieces that have been fitted to form a unit. This could be through a continuous weld or spot-welding or with nuts and bolts and washers. There are joints. Every place where there is a weld or a nuts-and-bolts joint, expansion rates will differ.

As well, the application of undercoatings must completely encase all of this in order to form a viable covering—it must be seamless. This doesn’t happen.

The next issue is that undercoatings historically were shot onto factory painted surfaces. In order for a coating to adhere, there must be the possibility of adhesion. Slick surfaces will not offer such adhesion possibilities. As a result, I have been able to remove portions of undercoatings on Volkswagens simply by using compressed air. Sometimes, I have been able to remove it in sheets, simply because of the lack of adhesion. I can imagine that vibration over the years helps to loosen poorly adhered coatings.