1963 Beetle Dilemma

Submitted by contributing writer; Jay Salser

This article concerns one of the latest queries from a customer. Eric restores original German Pierburg Fuel Pumps and had sold one to this customer. Now, Mark had a peculiar “situation”.

Could we help him?

And so, the 3 of us embarked on a several-day-sleuthing adventure which involved over a hundred e-messages and a number of personal phone calls.

The Customer, Mark Fairhurst, had purchased a Restored Fuel Pump from Eric. Mark messaged Eric with a problem which he was having.

Mark owns a 1963 RagRoof Beetle in nice condition. He’s owned the Bug for a number of years. The Engine was rebuilt during 2015 and had been operating optimally since then. The Carburetion was handled by a German Solex 28 Pict Carburetor. The Ignition included a recently replaced 6 Volt Coil and a German Bosch 009 mechanical-points Distributor. The Vacuum Port on the Carburetor was properly capped (since the 009 does not need vacuum assistance). The Cap, Points, Rotor and Condenser were relatively new.

The Problem: The car would start immediately and drive-away fine. About 20 minutes (some variance in the time) into the drive, the Engine would quit—dead quit! No amount of cranking would start it.

However, after sitting for about another 20 minutes (again variance in this time), the Engine would start and drive fine for yet another 20 +/- minutes when it would, again, stall. This would repeat itself until Mark eventually would be able to arrive at his destination.

If the car were to be started and left idling in the driveway, it would run for about the same number of minutes—then stall. Then, again, it could be started after about that same approximate wait-time and would run well once more.

Eric and I scratched our heads, asked a few leading questions and came up empty.

Since Mark had indicated that he lived in the Akron, Ohio area, I did a weather check. Akron was having fairly moderate weather with the daily highs being in the upper 70sF with perhaps an 80F thrown in there. Nothing like “hot” conditions at all.

Mark’s assumption had been that when the Engine would stall, the intervening time before it would again start was “cooling time” for the Engine.

There was talk about changing this part and that. But “throwing parts at a problem” usually is ineffective and results in a lot of money being spent with no systematic solution being sought.

I replied to Mark: “Mark,...I just checked the weather reports from your area of Ohio. You are having fairly moderate weather there with daily highs being in the upper 70sF and maybe an 80F thrown in there. That is not "hot" weather. I live in Texas and Summers here really are hot--100+ for days on end--esp. during August. We just completed almost the entire month of August in the 100F and higher range. I am having no problems driving my Beetle in this weather. That said--I am suspecting something else to blame for the stalling problem.”

I viewed “cooling time” to be irrelevant.

Mark reviewed for us some of the things which he had checked:

“Hi Jay. As you suggested, yes, it’s perfect driving weather here in Ohio. I have never checked the gas tank, thank you, will do and report. FYI, I did pull the plugs today, cleaned and reset and put back. All clean. Also went around to the easy to get at screws and bolts for tight fit and good contacts. I had read an article that talked about not overfilling the oil - as when it gets hot and expands, nowhere for it to go. As it was cold, it showed above the cut line on the dip stick, so I drained it down a little. Finally, started the Bug… it kicked on the first turn, let it run for about 10 minutes, sounded good and normal. I have an Oil Pressure Gauge and it showed around 35 psi at (cold) idle.”

My reply was: “Mark...Those are good things to consider.

Regarding Plugs: These little Engines will run on really bad plugs--even when one is left out, they will continue to run.

Your problem doesn't sound like ‘loose nuts/bolts/screws’.

I am working on the theory that the Carburetor's Bowl is running short of Fuel. Because it is not obtaining sufficient Fuel. When the Engine dies (from lack of Fuel), while you sit "to allow the Engine or ? to cool"--the Fuel begins to seep past blockages sufficiently to allow the Fuel Pump to again fill the Bowl. Enough to get down the road a ways before it runs dry/low again.

The reason for my theory is the way you describe the failure to run. Usually, an Electrical Failure would cause the Engine to fail immediately--and, to NOT restart. That's why I want to eliminate the beginning of the Fuel System--the Tank. Most people miss the point of the Fuel Supply--because we all have a "full Tank"--right. Let's see if we can disprove me on this first stage of "The Fuel Journey". Then, we can move along to the next stage of the discovery process.

[***Perform the following examinations out of the garage--in the open air.]

There should be a small diameter Vent Hose attached at the Filler Neck. Make certain that this Hose is not plugged. You can remove it from the Filler neck--blow through it or put compressed air through it from the top end--to see if there is a plug in that Hose. If it is plugged, a vacuum will be created inside the Tank. The vacuum will be broken as air eventually penetrates and by-passes the blockage. Make certain that the Tiny Metal Tube where the Vent hose attaches also is clear. If the Tank is factory, the tip of the Vent Tube (inside the Filler Neck) will be slightly crimped to avoid Fuel from sloshing out the Vent Tube when the Tank is very full.

Remove the Sending unit--use a flat-bladed screwdriver to remove the Sending Unit Cap, then remove the Screws. The Sending Unit should remove easily.

Now--using a flashlight, look into the Tank to see the lowest point--that will be where the Fuel exits the Tank. You should be able to see the long finger-like Fuel Fine-mesh Strainer sticking up inside the Tank. You will be checking for debris. If you see debris, it likely is plugging the Fine-mesh Strainer. If this is so, the Tank will need to be removed, drained and flushed using fresh, clean gasoline--swished around and allowed to drain from the exit hole.

Once you are sure that the Tank is clean--let us know how things are going to this point. What we are investigating is some manner of blockage which is keeping Fuel from flowing freely to the Fuel Pump and Carburetor. So--at this point, I am stopping this writing to hear from you. Thanks, Mark!”

Mark went to work examining the Fuel Tank and associated parts.

“OK, pulled the Gas Tank Vent Line and can easily blow thru, took a straw and was able to blow thru the Tank Neck Attachment Tube, it’s crimped on the inside but clear… pulled the top Gas Gauge assembly, looked into the Tank (gas at 1/2 filled), and could see the Mesh and it looked clear?, nothing around it or attached or built up… Line Filter has been recently changed… and so, I guess next is the Fuel Pump? It’s rather new(rebuilt) and attached at the beginning of the driving season, it leaked a little but a fresh seal took care of it. I pulled the Carb over the winter (Solex 28 Pict), cleaned in a vibration bath, and put in new parts, and seemed to be working at the beginning of the driving season. I did not update the little “auto” Choke assembly, they did not send new parts. I have drained the Float Bowl, and didn’t notice any discolored Gas or junk come out. I have pulled the Idle Jet, it seemed clean. What might be next steps? Mark”

“I'd think, checking Fuel Pump PSI......You could have a short pushrod or the flange is sanded down out of spec. Eric”

“Eric, what should be the Pressure coming out of the Pump? Mark”

I interject: “We'll have to address the Push Rod--once we know whether--or not--the Pump Stand is VW Factory Original or a Reproduction. But--we really need to know about the Pump Pressure first. It's the old game of elimination. Jay”

I say…”I believe that the Tank and Vent are fine. The Filter, also, if you are satisfied.”

And, so, we embarked upon a Fuel Pump investigation.

“Let’s go the next step—which is to check the Fuel Pressure from the Pump to the Carb. Then, we can proceed to A or B.”

I explain my reasoning: “I used to work, on the side, for a University, collecting museum specimens from the Amazon Rain Forest. We had “Keys” for identifying Snakes and Lizards. For example, at the front of the Key (Book) --the process would begin something like this: A. Smooth Scales B. Rough Scales. If B. skip to E. It would continue in this binary fashion until options would be narrowed to THE Species--unless it happened to be a new species.

This is what we are doing here with the VW Fuel System (more or less). Jay”

Mark: “Ok. Just ran it again, at Idle and it went for 13 minutes and just stopped? Something is or must be coming up to temperature and stopping the sequence. It’s always about the same amount of time… so am assuming it’s temperature related?”

“Also, how’s your Timing? Spark plugs are ok? Eric”

“Timing is good; put in New Plugs in the Spring, just pulled them last week and wire brushed them, cleaned and replaced. Mark”

“Mark, I think that we do not yet have a correct-a-mundo Fuel Pressure Reading. Well...you did dis-prove the ‘air bubble’ theory. Since we have traced the Fuel System front to back--it hinges upon Fuel Pressure And/Or what's happening in the Carburetor Bowl. What's happening is not having to do with allowing the engine to cool--it's waiting for the excessive gasoline to evaporate!

Bad Float Valve?

Bad Float?

Over-filling of Bowl results in excessive Fuel issuing from the Primary Discharge Tube? Jay”

Mark responds with Fuel Information from his perspective:

“I was reading about “vapor lock” last evening… of interest, all the symptoms I’m reporting are part of vapor lock. My problem has hit me (two years in a row) in the late part of the driving season and for me during the grandkids’ birthdays of October. My Fuel Pump sits right at the Manifold. The local gas stations should have switched to their “winter blend”… I will check with “Mikes” later this morning to ask exactly when he switched. If it should turn out to be vapor lock, how would I avoid this going forward? If it is vapor lock, why did it take 5 years to show up? Yes, I will get a better psi measure on the Fuel Pump. Mark”

“Ok gents. I bought a Fuel Pressure Gauge and tested. Sent you a 10 second video and still picture, not sure which one will get thru to you. Overall…. the Gauge is a combo psi and vacuum, all they had. I spliced in the hoses and the needle was not steady, and jumped around a lot… however never spiked over 3 at any time… but did dip down into the vacuum side to around “5”, don’t know what that means? Once the Motor was warmed up, it Idled (shaky needle) around zero to two. Finally, I did this in the garage and the Bug ran from 11:04 to 11:13 and then the engine just stopped running. Mark.”

“Well...That's VERY low Fuel Pressure!!! Hmmmmmmm. I just talked to the VW Engine Builder here. He says: ‘If the Carburetor runs out of Fuel--and the Engine is off--there's no way for any more Gasoline to fill the Carb Bowl.’ Jay”

Try the following: When the Engine dies--immediately go to the Engine Compartment and remove the Air Cleaner. Pull the Accelerator Lever (on the Carburetor) back and forth to see if Fuel is squirting from the Dispenser Tube (that tiny brass tube ). IF--Fuel IS squirting from the Dispenser Tube--it will be an Ignition Problem. Such as Bad Condenser, Points are closed, Bad Coil, Rotor Bad, (other?). This seems to be where we are presently. Jay”

Mark again--“The Bug ran and Idled (with me revving it here and there) from 10:04 to 10:28 and just simply stopped. As instructed, pulled the air cleaner off, stuck my head into the Carb, and “yes” it’s squirting a pin prick of gas from the small brass tube inside (Accelerator Pump Dispenser Tube). Nothing is “hot” to the touch… Coil, Distributor, Plug Wires, Fuel Pump, Generator, Oil Stick. OMG, in checking the Plug Wires, my #2 Plug Wire was loose from the Spark Plug and just lying there…I didn’t see this upon my “quick” look before starting. Also, no gas or oil dripping anywhere.”

Eric: “Mark, this does not sound like a Fuel Pressure Issue.”

Mark: “Ok… ran another test, started at 11:57 and it ran until 12:36. While Idling and Running and Revving, it sounded as strong as at anytime--normal. At the 12:36 mark, just stopped, period. I jumped in and tried to restart, and it turned over and began to try to start, but within seconds, died again. Meaning, to me, there was Gas, there was Spark, but would not catch and start. Help! Again pretty much nothing is hot to the touch, except the Distributor body. The plastic Cap is mildly warm, the Plug Wires are not warm even.”

Mark also found no Vacuum leakage. He also checked the Points—good gap. He turned the Engine using the Belt to watch the Points open and close—all good. Replaced Rotor with a new Bosch Rotor.

Restarted the car. It ran fine for a few minutes, then stopped—same 20-30 minutes.

I put in a call to the VW Engine Builder who suggested a check of the Condenser—telling me that when a Condenser is bad, it CAN cut out when it becomes hot. We never did get that far, however.

“Gents… I am confused completely! Just shut the Bug off at 2:50… that’s 43 minutes without any hesitation or hiccups or anything. There’s nothing different from yesterday other than I pulled the Distributor Cap, checked the Points Gap (but changed or altered nothing), cleaned the Contact Points a little, and the weather today is noticeably cooler, 60F.

If by slightly cleaning the Distributor Cap Contacts made a difference, then this is something I should do often. However, that would not explain why the Bug started and drove well for 5 years with me virtually doing nothing. Next steps? Mark”

Jay: “Mark, I want to thank you for being patient. You cannot believe some of the responses which Eric and I receive. One person actually cussed us after the first two questions, saying that we were questioning his mental capacity. Well, Mark--it is not that at all. It's simply wanting to learn something in an organized manner.”

As we continued our search process, Mark exclaimed: “I did see a broken wire going to the Choke Heater Element and am replacing the connection today. Replacing items I’m sure didn’t hurt, either. What I’ve learned (so far) is that for 5 years I have been very lucky not to experience any major issues. But, going forward, I need to keep things clean and tight and pay attention to any moans and groans.”

We messaged back and forth, the Three of us, discussing other aspects of this problem.

Mark performed another Fuel Pressure check, using a different Pressure Gauge. At first, there would be proper Pressure—then, it would drop to about 1 psi at Idle. Here, again, this was puzzling!

“It occurs to me--One Thing which we did not completely address....was the Fuel Line (inside the Chassis) from front to back. Disconnect the Chassis Fuel Line under the back of the car where it connects to the Line which goes through the Firewall Tin. When this Hose is disconnected--does the Fuel run freely from the Fuel Tank and out this Hose? If not… there could be a blockage which might allow some Gasoline to be pulled through the Line--by the Pump--but which would not be sufficient to keep the Carburetor Bowl filled when the car is running for a prolonged amount of time. Fuel SHOULD run freely from this Line! (unless the rear of the car is raised).

Do the same operation for the Hose which passes through the Firewall Tin to the Fuel Pump—again, Fuel should run freely through this section of the Hose (unless the rear of the car is raised). If we are getting only a “dribble” or drips and the car is sitting level, something is impeding the flow of Fuel from the Tank. Use a container to contain the Fuel emitted to be able to understand how much Fuel is emitting for each of the two above experiments.”

“Hmmm, when I previously replaced the Fuel Line Filter mounted at the low point behind the back drive wheel, the Gas ran out OK. But I did not pay close attention; will redo and let you know. Mark”

Later…..Mark Reports:

“Gents. I am humbly reporting that the dilemma seems to be solved… Clogged Fuel Line… 50 lbs of air pressure blew out a grimy snot-ball of grey brown sludge.

Apparently the Fuel Line was 75% blocked with “varnish sludge” from using 87 Oct Gas for the past 7 years and it finally caught up with me.

I’m guessing, but apparently a full Line of Gas and a Carb Bowl full of Gas, plus a 15% trickle, runs the Motor for 15-20 minutes, based on the load of driving or idling.

I Pulled the Tank, cleaned the Outlet “Valve” and the Tank as well as possible

Cleaned the Fuel Line front to back, cleaned the Carb…reassembled it and the Engine started right up and drove well all over--up and down hills, fast, slow, long Idle…ran strong.

Lessons learned: Run high Octane Gas to help keep the Lines cleaned. Be prepared to blow the Lines clear when I start feeling a hesitation. Check for tight nuts and bolts and wires and grounds. Check tolerances for Plugs, Points and keep the Rotor Contacts clean.

Overall, thank you for helping me to run through a check list of possibilities. It made me think and look and get to know the Bug.

Eric: “It happens! It always helps to keep the Fuel Lines clean.!

Jay: “Hurrah, Mark! Yes!!!!

I always try to begin with the easiest thing and work my way from there.

The only two problems would have been Fuel Deprivation or an Electrical Problem.

You fairly eliminated the Electrical (Ignition)--BUT, you DID find the Broken Hot Wire to the Choke Heater Element! That was a good find and very important! (there should be superior gas mileage now and cleaner exhaust/plugs/etc.)

Checking all of these things left the one possibility--which I asked about at the very last--simply because you had not assured me of having checked the Fuel Flow from Tank—through the Chassis Line to the Firewall. Not wanting to overlook even one Variable--I asked if you had checked Fuel Flow there. This discovery also explains why you could not obtain a “good” Fuel Pressure reading and why the PSI jumped up and down and fell off significantly when the Carb came to Idle (the Fuel supply was dwindling!)

I want to thank you for being so patient during the process! We conducted a good, scientifically focused examination and can now be assured of good operation of your Beetle. Most people want to throw parts at problems--this results in high cost and, usually, no successful conclusion. And, IF the car is put back into operation--there is no way to know which variable was THE one which needed attention!

My conclusion would not necessarily include using a Higher Octane Fuel. But, it WOULD emphasize the replacement of Fuel Hose with Ethanol Resistant Hose (now available in the correct Inner and Outer dimensions). Ethanol damages the inner core of Fuel Hose. The damage can result in particles which have broken away and can clog the Hose. I also recommend the replacement of the Fuel Hose between the Fuel Pump and the Carburetor ANNUALLY especially, because it is under pressure. If it leaks/ruptures, a Fuel Fire is sure to happen!