Engine cuts out in 3r & 4th Gear.

Might possibly be fuel line vapor lock, especially if it was a hot day.  The exhaust system cooks the gas in a fuel line, which makes a bubble in the line stopping the fuel flow.  When you stop for a few minutes, the hose cools off, the gas re-condenses and flows again so you can start it.  Drive a little bit and it happens all over again.

Follow the gas hoses back from the pump to the carburetors and also from the pump back to the firewall and make sure none are lying on any of the engine tins where the exhaust or engine heat could heat them up, causing the gas within to percolate and make gas bubbles, keeping the fuel from flowing.

This is especially true for the mechanical fuel pumps - They push gas well but can’t suck very well.  They have a hard time overcoming fuel hose vapor lock ahead of the pump because they are gravity-fed from the tank.  If the vapor lock occurs in the hose before it gets to the pump, well, the pump sucks but can’t get any fuel past the vapor lock.  If you upgrade to an electric rotary pump up front, under the gas tank, vapor lock won’t happen because the pump continues to push fuel through the hose and quickly overcomes any vapor lock.

If none of this applies, then I suspect you have a Pertronics distributor module that’s going south.

It wouldn't be the pivot pin on the fuel pump lever has backed out by any chance. Had it happen to me. Car would idle and run fine up to about 3K RPM and then die. I would get down the road a little bit, into about third gear and the car would quit. Would start again after a bit of cranking and idle no problem. Just by shear luck I noticed the pin was almost out of the base of the fuel pump. Pulled the pump off and peaned the ends of the pin and problem solved.

^^That, Too!^^
That happened to Carl Berry at Carlisle one year,  Same symptoms, too!  Alan Merklin pulled the pump and inserted a small screw into the arm where the pin was gone and fixed it!  

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My brand new VS did almost exactly the same thing (back in July, 2013).

I could drive it around the neighborhood with no problems. I could drive it on the freeway — up to a point.

When I got about five miles down the road, it would sputter, then stall, and I'd coast to a stop. It would also start right up again. I could drive it home from there, again on the freeway, with no issues.

If I started out again from home, it would repeat this behavior, stalling at the same spot on the freeway, and again drive home OK after a restart.

The clue was that it would stall just after the beginning of a gradual uphill section of freeway.

The experts reading this may have already diagnosed the problem.

It was the float levels in the carbs, which had never been set properly. They were too low, not allowing the bowls to fill to a proper level. So when the throttle was opened past a certain point and held there, the bowls would empty and the carbs would stall out.

Even if the carbs are brand new (maybe especially if they are brand new), setting the float level is a key part of dialing them in. It's not necessarily set correctly from the factory.

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"mechanical fuel pump, fuel regulator set at (6 lbs psi)."

Is six pounds right for Dels? I thought 3.5, same as Webers.

I know I've said this before, but to those that weren't here:

The numbers on a regulator mean ABSOLUTELY NOTHING. The regulator should be set with an actual gauge T'ed into the carb feed lines, while the engine is running.

Webers/Dellortos get 3 to 3.5 psi. Solex/ Kadrons get 1.5 psi.

If the fuel pump is electric, many are self regulating. Most for American V8s are not and require an external regulator.

A mechanical pump doesn't need a regulator. They should be checked with a gauge and a stack of gaskets under the pump to set pressure. I had one that required SEVEN gaskets to get down to 1.5 psi.

If carbs are new, they should be disassembled, thoroughly cleaned, float level set, synced, and tuned. Period. Carbs come dirty, whether they are shiny on the outside, or not.

Along with the timing and general health of the ignition system from coil to points/trigger, cap, rotor, wires, and plugs. 95% of carb problems are ignition problems.

And an ice cold valve adjustment to start. 'Cause mechanical adjustment of the engine(which is simply an air pump) is important. 

I noticed you have the CB turbo hats. Is that a new addition or have they been on there a while?

If they've been on there with no trouble, ignore this. If they're new, the hats could be close enough to the velocity stacks to cause high load/rpm restriction. Turbo hats are shorter and require shorter stacks IMHO.

If you have Jet Doctors(little brass tubes near the velocity stacks) this could(ahem) be the problem. I've experienced this first hand.

Hello to all.....thanks for all your comments and ideas, it looks like my next steps are to pull the fuel pump and look it over - probably will replace it completely since I don't know how long it's been operating in the car.  The CBD Turbo hats were installed 2 years ago - and worked fine. Will need to get a gauge to measure the actual PSI coming out of the fuel pump and into the carbs....has anyone used the one's that are installed on the fuel line? I had one on my Cobra fuel injection system, but that's been over 10 years ago. Will let you all know what I find! Thanks again for all of your support and suggestions!

Thanks about the Turbo hats.

The gauge can be temporary, permanent not necessary. Many sources sell a low pressure/vacuum combo gauge for testing:

https://www.harborfreight.com/...glhdr6RoClQMQAvD_BwE

@DannyP posted:

Thanks about the Turbo hats.

The gauge can be temporary, permanent not necessary. Many sources sell a low pressure/vacuum combo gauge for testing:

https://www.harborfreight.com/...glhdr6RoClQMQAvD_BwE

Great.....thanks for the gauge info.....

Hello to all......well, got the new fuel pump installed along with replacing the fuel line between the new Fuel filter and pump then took it for a test drive (starts fine and idles good, rev it works good not missing at all) ......no improvement, when I hit third gear it ran for a bit and then just stalled out. waited a minute or two and started it up and did the same thing. What do you all think my next step should be? I did go out and purchase the fuel gauge from Harbor freight but haven't used it yet, it's really going to be a Pain in the A - -  getting it onto the fuel line on the carbs since the fuel input ports are facing to the interior fender walls (not much room back there).......Thanks'

Looking forward to your feedback!

@Sacto Mitch posted:

.

My brand new VS did almost exactly the same thing (back in July, 2013).

I could drive it around the neighborhood with no problems. I could drive it on the freeway — up to a point.

When I got about five miles down the road, it would sputter, then stall, and I'd coast to a stop. It would also start right up again. I could drive it home from there, again on the freeway, with no issues.

If I started out again from home, it would repeat this behavior, stalling at the same spot on the freeway, and again drive home OK after a restart.

The clue was that it would stall just after the beginning of a gradual uphill section of freeway.

The experts reading this may have already diagnosed the problem.

It was the float levels in the carbs, which had never been set properly. They were too low, not allowing the bowls to fill to a proper level. So when the throttle was opened past a certain point and held there, the bowls would empty and the carbs would stall out.

Even if the carbs are brand new (maybe especially if they are brand new), setting the float level is a key part of dialing them in. It's not necessarily set correctly from the factory.

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Sorry I missed answering this reply, NO HILLS here in NC, all flat....thanks!

Is it possible that the fuel tank isn't venting? It's pretty easy to test the theory. Anything blocking that venting, like something is clogging the vent line, or if the check valve stuck closed, you'd get symptoms a lot like what you're describing.

Two things to think about:

1.  Is there some crud ( rust or dissolved, sprayed-in tank liner ) obstructing the little screen in the bottom of the gas tank causing fuel starvation after a minute or so.

2.  But before you go hauling the gas tank out to check that, I would check or replace your distributor electronic module.

Larry,

I had a problem similar to yours at one time.  Engine started fine and ran fine just putting around town.  Could rev it and not cause anything evil.  But romp on it getting on the freeway and it was sputtering out before getting very far down the road.

I'd pull over to the side and let it idle sickly, or just sit with ignition on (electric fuel pump) and in not much time it would start/run dependably again  --  until the next time I romped on it on the freeway.

Basically, it was running out of gas, kind of like @Sacto Mitch.  In my case the float bowls were emptying at sustained high rpms faster than they were being refilled.  Sitting long enough for the electric fuel pump to refill the bowls, or in your case cranking on the engine long enough for the mechanical fuel pump to refill the bowls was good enough to get going again.

I did all the crazy things.  In my case it wasn't the float levels.  What it turned out to be was that cheapo fuel pressure regulator (like the one you probably have.).  I don't know what was wrong with it and never cared to find out.  I presume it was somehow choking the fuel flow. I replaced it with another similar cheapo and the angels started singing.  After reading that the cheapo regulators are exactly what they are (cheapo) I replaced the replacement with a Malpassi and never had the problem again.

In your case, with a mechanical fuel pump I'm not sure you even need a pressure regulator.  Real VWs didn't have them. I'd let someone else fact-check if that's true.  If so, then take the regulator out of the fuel line, drive around without it and see what happens.  Seems like it might be the fastest/easiest step of elimination.

on a stock VW bug you often get the metal gas line in the tunnel  clogged  which cuts down the gas flow.

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Larry, my problem wasn't the hills, per se.

But that's where I was starting to open the carb butterflies wider for a sustained amount of time. The same thing would happen if I tried to accelerate rapidly on a flat stretch.

If you've got typically stock VW gearing, you're probably not spending too much time in 1st and 2nd before you get up to 3rd, where you say the trouble always starts, so it looks to me like as soon as you make any kind of serious demand on the carbs for more than a few seconds, they're running out of fuel.

In any case, all of the old school authorities on setting up these engines always start at the same place — measuring the fuel pressure the carbs are seeing with an inline gauge. It really shouldn't be that hard to find a convenient place in the fuel line to do this, but even if it is, you're wandering in the dark and just guessing until you do.

Once you know, you know, but you'll be wasting time and money, and probably just getting more frustrated until then.

Good luck.

.

@DannyP posted:

I know I've said this before, but to those that weren't here:

The numbers on a regulator mean ABSOLUTELY NOTHING. The regulator should be set with an actual gauge T'ed into the carb feed lines, while the engine is running.

Webers/Dellortos get 3 to 3.5 psi. Solex/ Kadrons get 1.5 psi.

If the fuel pump is electric, many are self regulating. Most for American V8s are not and require an external regulator.

A mechanical pump doesn't need a regulator. They should be checked with a gauge and a stack of gaskets under the pump to set pressure. I had one that required SEVEN gaskets to get down to 1.5 psi.

If carbs are new, they should be disassembled, thoroughly cleaned, float level set, synced, and tuned. Period. Carbs come dirty, whether they are shiny on the outside, or not.

Along with the timing and general health of the ignition system from coil to points/trigger, cap, rotor, wires, and plugs. 95% of carb problems are ignition problems.

And an ice cold valve adjustment to start. 'Cause mechanical adjustment of the engine(which is simply an air pump) is important.

this

Agreed.....next step is to put the Fuel pressure gauge on and see what is really going on there and ensure that the correct pressure is being applied as you stated 3.0-3.5 PSI.

Thanks

@RS-60 mark posted:

Larry,

I had a problem similar to yours at one time.  Engine started fine and ran fine just putting around town.  Could rev it and not cause anything evil.  But romp on it getting on the freeway and it was sputtering out before getting very far down the road.

I'd pull over to the side and let it idle sickly, or just sit with ignition on (electric fuel pump) and in not much time it would start/run dependably again  --  until the next time I romped on it on the freeway.

Basically, it was running out of gas, kind of like @Sacto Mitch.  In my case the float bowls were emptying at sustained high rpms faster than they were being refilled.  Sitting long enough for the electric fuel pump to refill the bowls, or in your case cranking on the engine long enough for the mechanical fuel pump to refill the bowls was good enough to get going again.

I did all the crazy things.  In my case it wasn't the float levels.  What it turned out to be was that cheapo fuel pressure regulator (like the one you probably have.).  I don't know what was wrong with it and never cared to find out.  I presume it was somehow choking the fuel flow. I replaced it with another similar cheapo and the angels started singing.  After reading that the cheapo regulators are exactly what they are (cheapo) I replaced the replacement with a Malpassi and never had the problem again.

In your case, with a mechanical fuel pump I'm not sure you even need a pressure regulator.  Real VWs didn't have them. I'd let someone else fact-check if that's true.  If so, then take the regulator out of the fuel line, drive around without it and see what happens.  Seems like it might be the fastest/easiest step of elimination.

Yes, the regulator will be the next thing that is tested once the Pressure gauge is put on line and see what it's interaction is with the system.....

Remember, you can have adequate pressure (on the gauge) yet still not have adequate "flow" to the bowls.  You need both, pressure and flow.  If something is restricting the flow (it could be as simple as a kink in the hose, or a clogged filter, or a defective regulator) then the float bowls might empty at sustained higher rpm, even if fuel pump pressure is adequate.

I think your Dells will be much happier at 2.5 psi.  I think you will be much happier with a Malpassi regulated electric fuel pump.

More is not better when it comes to fuel pressure.  You only need enough pressure to get the fuel to the bowls, with enough flow to fill them as fast as the flow being sucked out of them by the engine.  Not enough flow; you run out of gas.  Too much pressure; you overpower the float valve (overfilling the bowls and flooding the engine with raw fuel, as-in really bad).

An advantage to an electric fuel pump is its pressure is constant, it doesn't go up and down with RPM.  Malpassi has a nice combination regulator / filter that also happens to look great in your engine bay.  You'll still need your gauge to set the pressure, even if it "says" the pressure was set before shipping.

I can spend more of your money and time, if you ask.  Actually, you don't even have to ask. 

PS Edit:  Remember --  line pressure drops when float valves are open.  So, with mechanical fuel pump the engine has to be running to get fuel pressure, and with the engine running at least one of the float valves is as likely to be open as not.  You'll need to start the engine to get the bowls full.  Stop the engine and then disconnect the fuel line from carb(s) and plug it.  Start the engine and check psi at various rpm (unplugging the plug between rpm tests).  You need to complete this before the float bowls run out of gas.

Hello to all......got the pressure gauge hooked up and found out that I was pushing 3.4 PSI to the carbs. Adjusted the REG to put out 2.5 and took it for a test ride. Same results (sputtering and stalling) at the end of the run where I needed to go into third gear. Nursed it back home and noticed that my PSI was down to 1.2 PSI, when I tried to go in and readjust it, I got it back up to 2.5 PSI, when I was adjusting the gauge, the reading was jumping (not past 3 PSI) to 2.5.

My next step is to eliminate the REG all together and see what pressure the pump is putting out by itself. I will look into the combo REG & Filter 9 Malpassi) that Mark mentioned above. More to come....

Find the kink in the line. Or the obstruction. Could be in a hard line too. Trace it all.

If I understand correctly you have good pressure and flow at idle and low throttle settings, but as soon as the demand goes up the pressure goes down. If that's true, then you have a couple possibilities.

1) The pump is failing. Easy to test, just swap in a new pump.

2) There's an obstruction in the feed line between the tank and the pump. Easy to test, use a small remote fuel tank plumbed directly into the pump. (Possible causes: collapsed fuel line, non-ethanol resistant fuel line issues, clogged filter or filter in the wrong way round, kinked fuel line either hard line or flexible, clogged fuel line, clogged tank outlet)

3) There's a vacuum developing in the tank when fuel demand is high. Easy to test, loosen fuel cap and see if it goes away. (Possible causes: Do you have ethanol resistant fuel line for your vent tube? Is teh check valve ethanol resistant and in the right way, and not clogged? If you have a cap vent only is it clogged?)

I don't think that if the obstruction was between the pump and the carbs the pressure would drop much or at all.

Hello to all....it's been awhile since I was able to get back to this project, but my schedule has cleared up, so I am back at it again. In answer to Michaels questions and suggestions above -

1) The pump is failing. Easy to test, just swap in a new pump. Put in a new pump and no change

2) There's an obstruction in the feed line between the tank and the pump. Easy to test, use a small remote fuel tank plumbed directly into the pump. (Possible causes: collapsed fuel line, non-ethanol resistant fuel line issues, clogged filter or filter in the wrong way round, kinked fuel line either hard line or flexible, clogged fuel line, clogged tank outlet) I have this configuration ready to go, thats the next thing to be eliminated

3) There's a vacuum developing in the tank when fuel demand is high. Easy to test, loosen fuel cap and see if it goes away. (Possible causes: Do you have ethanol resistant fuel line for your vent tube? YES, and it is clear. Is the check valve ethanol resistant and in the right way, and not clogged? No Check valve, If you have a cap vent only is it clogged?) Checked all above and all is good

I did pull the Fuel Pressure controller out and without it the Fuel pump is pushing close to 3.2 PSI to the Carbs with it back in its at 2.2 PSI (set to drop 1 PSI)  and that appears to be working correctly.

My next step is to put in a small 2 gallon tank (behind the seats) and new fuel and fuel line directly to the input of the Fuel Pump, eliminating the regular Tank and connecting line. This is my last test scenario since everything has been tested or replaced. The Next step will be an exorcism!!   

@Larry Scislowicz posted:

I did pull the Fuel Pressure controller out and without it the Fuel pump is pushing close to 3.2 PSI to the Carbs , , , , , ,

You didn't say you took a test drive with the regulator removed.  Did you?

3.2 psi unregulated should be within pressure limits of the Dells, which allows you to see what happens on test drive without a possible suspect regulator installed.

I even hate to bring this up, but…

You aren’t running a Pertronix points replacement module by chance, are you?

95% of all "fuel" problems are spark. I reread your description in the opening post -- at this point, I'd ensure the module and coil are both good. It sounds like one or the other is bad.

Everybody's got their own way of checking them -- I'm a simple man, so I just temporarily replace with "known good" and go from there.

I recently had my car take a dump in traffic all of a sudden. The coil just quit, deader than Caesar. In hindsight, I was noticing some similar hiccups while driving that I couldn’t readily diagnose. A new coil solved all issues.

Speaking from personal experience, once your mind is made up about the nature of a problem, ignition problems feel a lot like fuel problems. The blinders come off hard.

It might be fuel, but I’m guessing not.

^^ Me, too.

Those of you who, like Stan, will remember some problems I had in my Speedster on one of our Tours de Smo' that were difficult to diagnose.  The one that at first seemed most like an ignition problem (dying on the highway after cruising for a while) turned out to be gas tank venting, and sputtering and running like schlitz turned out to be rust in the distributor (fixed with WD-40, emery paper, and the spring from a Bic pen.  Gotta love Charleston humidity - NOT!

The point of the preceding ramble is that it's not easy to diagnose some of the issues out "glorified lawnmower motors" can throw our way.  I'm betting on ignition, in the OP's case, but I'm also hedging a bit.

.

@Stan Galat posted:

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...95% of all "fuel" problems are spark...

.

For most of us.

But most of us have started out by first going through the basics.

Number one is checking actual fuel pressure (as has now been done).

Number two is doing the fundamental setup for new carbs (which still has not been verified as far as I can tell). Yeah, that means jetting, linkage adjustment, left-to-right synching, but it all begins with a mechanical inspection (including proper butterfly movement, spring tension, etc.), thorough cleaning, and setting the float levels.

I wouldn't be harping about this again but for the fact I had almost the identical symptoms to what the OP first posted about and float levels were the direct cause.

Good, steady idle, with a sharp stumble and complete stall when the taps were opened. And then, an immediate, easy restart, and smooth running if the throttle wasn't opened too far again. That on again, off again behavior with an easy immediate restart are hard to explain with faulty ignition bits that tend to create more erratic operation, often linked to parts heating up and not working again until they've had a chance to cool.

Pulling and tearing down carbs is not an easy task for the novice (like me), but it's part of the drill that must be done in the beginning if we don't like chasing our own tail.

I get the impression the car is new to the OP and that he doesn't know a lot about the previous history. Is there any indication the engine is new or recently rebuilt, or that the carbs are newly installed?

.

My last post on the subject, as I already feel like I'm beating a drum.

But if a car is running well, then...

@Larry Scislowicz posted:

... all of a sudden, I lost power, was giving it the gas and nada!, no power. Finally, it stalled out and I pulled over to the side of the road.

... it's generally not fuel, especially given the exceedingly sketchy nature of all things Pertonix. With a fuel problem, there will generally be a miss or spit (catching and sputtering). If it feels like a switch shutting off, it's generally a switch shutting off.

Again, I have no dog in the hunt (and diagnosing anything over the internet is a fool's errand), but 95:5 is about right on ignition vs fuel with issues exactly as described.

@Stan Galat posted:

I even hate to bring this up, but…

You aren’t running a Pertronix points replacement module by chance, are you?

95% of all "fuel" problems are spark. I reread your description in the opening post -- at this point, I'd ensure the module and coil are both good. It sounds like one or the other is bad.

Everybody's got their own way of checking them -- I'm a simple man, so I just temporarily replace with "known good" and go from there.

No Pertronix Points Module.....

Anytime I've had fuel issues on a car it sputtered before giving up.

Every time I had an ignition problem, it shut off like a switch being thrown.

Anecdotal data for sure, and I'm not challenging anyone's diagnosis.

Thankfully, this has happened only a handful of times over 55 years plus of owning lots of different cars, and about a half dozen of our sewing machine engine powered conveyances.

It will get sorted, I hope with not much more frustration.

@RS-60 mark posted:

You didn't say you took a test drive with the regulator removed.  Did you?

3.2 psi unregulated should be within pressure limits of the Dells, which allows you to see what happens on test drive without a possible suspect regulator installed.

Yes, took it for a spin with same results of engine cutting out, after letting it coast to the side of the road and wait a minute it starts right up and limped home in 2nd gear....

@Panhandle Bob posted:

Anytime I've had fuel issues on a car it sputtered before giving up.

Every time I had an ignition problem, it shut off like a switch being thrown.

Anecdotal data for sure, and I'm not challenging anyone's diagnosis.

Thankfully, this has happened only a handful of times over 55 years plus of owning lots of different cars, and about a half dozen of our sewing machine engine powered conveyances.

It will get sorted, I hope with not much more frustration.

"Anytime I've had fuel issues on a car it sputtered before giving up." This is what I am experiencing at this time.....

@Sacto Mitch posted:

.

For most of us.

But most of us have started out by first going through the basics.

Number one is checking actual fuel pressure (as has now been done).

Number two is doing the fundamental setup for new carbs (which still has not been verified as far as I can tell). Yeah, that means jetting, linkage adjustment, left-to-right synching, but it all begins with a mechanical inspection (including proper butterfly movement, spring tension, etc.), thorough cleaning, and setting the float levels.

I wouldn't be harping about this again but for the fact I had almost the identical symptoms to what the OP first posted about and float levels were the direct cause.

Good, steady idle, with a sharp stumble and complete stall when the taps were opened. And then, an immediate, easy restart, and smooth running if the throttle wasn't opened too far again. That on again, off again behavior with an easy immediate restart are hard to explain with faulty ignition bits that tend to create more erratic operation, often linked to parts heating up and not working again until they've had a chance to cool.

Pulling and tearing down carbs is not an easy task for the novice (like me), but it's part of the drill that must be done in the beginning if we don't like chasing our own tail.

I get the impression the car is new to the OP and that he doesn't know a lot about the previous history. Is there any indication the engine is new or recently rebuilt, or that the carbs are newly installed?

.

In answer to your questions (in yellow above) Engine & Carbs have been running well since I bought it 4 years ago. Problem is consistent and rears its head when the I shift into 3rd of 4th and then it sputters like someone shuts off the gas and finally go's out. Starts fine and runs well in 1st and 2nd gear. I'm close to have checked everything in the "fuel delivery system". The only thing left is to plumb in the small fuel tank and line replacing the installed system and take it for a spin and see what happens.........

I have the same set up you do, 2110  but with an electric fuel pump, a filter right after the tank and before the pump, and another metal filter on the fuel line below the engine bay and ahead of the carbs. No fuel pressure regulator as I'm under the impression, based on reading and hearsay, that a regulator is neither required or recommended with Dells.

DannyP rebuilt my Dells, and Stan tuned them for me. No issues for a couple of years now.

If I read correctly, you bypassed the regulator for testing purposes. But did you bypass it and then test drive the car?

I know how frustrating this must be for you.