Some questions for my 40hp 1200 - 1965

[awm440]

Hello all,

I have a Dunebuggy with a stock 65 beetle components. It's currently still a 6v system, but is run on 8v. 1200 - 36 or 40hp - 28pic carb.

I took it out the other day, and it ran fairly well all around town. I put about 50 miles on it that morning, maybe more. Then, later in the day when I went home, it started to pop and hesitate on me during acceleration. I noticed that if I tried to accelerate at a normal rate, it would crack, pop, hesitate, and it tried to stall out on me a number of times. Until eventually, two blocks from home, it did stall out. I waited a few minutes and it did start back up again and I made it home fighting to keep it alive. The slower I accelerated, the better it was. I noticed it ran better on flat roads than it did on hills.

My initial guess is the fuel pump. However, I took it off tonight and doesn't look particularly worn out. If I push on the flange fuel comes out.

So, I have some concerns that it might be as simple as the choke on the carb not working properly. It started to run better once it had been running, but then still did the same behaviors fairly often near the end of the trip, so I'm doubtful of that. Maybe dirt in the carb? Perhaps the coil is going bad? Has anyone had a similar experience?

2. I plan on installing a 12v conversion kit with an alternator. Do I need to get the generator fuel pump or the alternator fuel pump? I know they have the long and short push rod respectively and you have to use the right one.

3. I've also been thinking about replacing the stock distributor with an 009 or a SVDA. I'm not really sure what the stock distributor is or what would be the best bet for me. I want to be able to drive the car often and reliably.

Any help you can offer would be much appreciated.

[EVfun]

Sudden failure to fire under load... that often is due to ignition system issues. I would check the running coil voltage, cap, rotor,, points, condenser, coil, plug and coil wires, and plugs. Then I would chase through the system feeding power to the coil as some issues may only show with the vibration from driving (buggies tend to shake and rattle more than Bugs.)
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[awm440]

It definitely bounces around a lot. Thanks, I will check it out. I hate to put any money into the 6v, I may just change it out and go from there. I'm just hesitant to do that and then have it not run at all after the conversion.

[thomas.]

If I were you I would fix any problems before any major changes. Like a 12 volt conversion. Also , I would check that the distributor is advancing properly. You might have a plugged vacuum line. good luck

[Q-Dog]

How long have you had this car? How much have you driven it? When was the last tune up?

You can't just look at a fuel pump to tell if it is good. Remove the line from the carb and put it in a jar ... crank the engine. Does it pump fuel? How much? You can also put a pressure gauge in the line to measure the pressure. Too much pressure can flood the carburetor, too little will starve the engine for fuel. How much pressure does yours have? Lots of new, cheap pump make too much pressure.

Troubleshooting engine problems is a methodical process. Guessing at problems and changing parts will likely provide you with an eventual solution, and a box full of removed parts that were perfectly fine.
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Brian

'69 Dune Buggy
'69 Beetle Convertible
'70 Beetle

[awm440]

[awm440]

[Sharp64]

Why the insistence on changing out the 6v system? With clean connections and a good battery they work fine. I'd agree with above to restrain from throwing parts at the problem and actually do testing to truly figure out what the issue is. If the fuel pump is shooting fuel across the room it sounds to be ok. By the same token, you mention it being possibly a new fuel pump and these infamously have too much pressure which may be flooding the engine. It may help as well to post up some pics of the engine along with what distributor and carb you're running. Distributor number is on the backside typically or possibly on the Bosch badge. Carb number is on the left side on the bowl. Any idea on the history of the car? Has it sat for any length of time? Have you checked the fuel lines for crud? I chased a fuel gremlin for weeks before realizing the treatment someone used to seal my gas tank had come loose and was clogging the valve on the tank. You may have crap clogging your accelerator pump and it's running on just the idle circuit.
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1960 Indigo Blue Ragtop (Blue Barry)
1967 Ghia
1985 Westy Money Pit
“...some men aren't looking for anything logical, like money. They can't be bought, bullied, reasoned, or negotiated with. Some men just want to watch the world burn.” - Michael Caine

[awm440]

[Sharp64]

Headlights are dim most likely because your connections are corroded or you have poor quality butt connectors. Clean up all your connections and solder your wires together and your 6v headlights will be fine. These cars were produced for over 20 years running on 6volt with no issues and millions were made. Millions more still have 6volt. Ultimately, your car, your choice. Let me know if you want to sell any of the 6volt components if they're OG.
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1960 Indigo Blue Ragtop (Blue Barry)
1967 Ghia
1985 Westy Money Pit
“...some men aren't looking for anything logical, like money. They can't be bought, bullied, reasoned, or negotiated with. Some men just want to watch the world burn.” - Michael Caine

[wfernandot]

I am running into a similar problem. Mine is also a 6v beetle sedan. Initially the car got very poor performance (max speed 35 mph). To improve it, I put a new fuel pump and a new coil and Pertronix distributor. My problem got fixed instantly (60 mph). But after two weeks, one day going up a long soft hill it started chugging and eventually stopped. I let it rest few minutes and restarted again without problems. now more frequently it does the same thing specially if drive fast (50 mph). If I Drive slowly and very gently does nor seem to have much of an issue, but if a I sprint and run a bit after 500 yards will chug again. Then if turn off the engine and restart, it comes again normal and idles normal starts and sprints normal one or two times and then start chugging again like the reservoir inside the carburetor empties. I have rebuilt he carb and washed the jets twice in an ultrasonic bath. I am running out of ideas. By the way I rebuilt the car last year and I put a new gas tank.

[EVfun]

What you are describing sounds more like a fuel delivery issue. The key difference is that you get a little good time under load before it goes bad.

With the fuel system all intact as driven you might try a cranking fuel pump delivery test. It isn't a complete test because the cranking rpm is a lot less than the running rpm. As I think of the fuel system you have a tank that may still have a fine bronze mesh strainer (often call a sock). It can get plugged up bad. You have a hard line running end to end in most bugs and buggies, it can fill with corrosion. You may have 1 or more inline fuel filters that should be replaced if even slightly questionable. You may have a fuel filter in the top of the fuel pump and they can get plugged and limit fuel. This is your fuel system check points. Water in the fuel system can plug paper type fuel filter elements too, so look for signs of water contamination.

It could be an ignition problem, but I suspect that first if a problem happens instantly when you hit the throttle, especially if it is more pronounced at high rpm. Fuel system problems typically give you a moment of good running when you hit the throttle, the time it takes for the float bowl to run low. Often fuel delivery problems happen at lessor loads at moderate rpm and it greater loads at higher rpm (when the fuel pump is trying harder.)

Of course I may be completely off-base. This is just ramblings on what I look for, to suggest where to start diagnosing a running issue.
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[slo356]

When was the last time you serviced the ignition? Check the points condition and gap/dwell, replace or reset if necessary. IF they are super pitted or burned, your condenser may be bad. If you have an old one that you know is ok, I would install it to eliminate this as a possibility. Inspect the distributor cap closely for small hairline cracks.

I echo not changing anything alternator wise et al until you have cured your current problem. Btw, I would stay away from 009's unless it is an original German piece.

Good Luck finding problem and please report back as to what you find…it adds value to the Forum...
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'65 T1 Sedan
'87 T3 Syncro

[herbie1200]

For headlight the test is to measure voltage directly on bulb socket when they are on. Bad connection can drop from 6-7V down to 4V.

I keep my 6V system, all in order plus some relais, it is now perfect.

[andk5591]

agreeing with fuel delivery. And something that I have not experienced, but have seen posted on here is the issue being more of a problem ast things warm up - I think the pushrod starts sticking? If its intermittent, buy a cheap fuel pressure gauge (low pressure) and T it into the fuel line to the carb. Then when it does it, run back and check the pressure.

12V - 6 V. Personally will never have a 6V car...Just my preference. And if you upgrade the 1200 and go to a 1600 or something later, the parts can be transferred over....
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D-Dubya Manx clone - 63 Short pan,1914.
Rosie 65 bug - My mostly stock daily driver.
Woodie 69 VW woodie (Hot VWs 7/12).
"John's car" 64 VW woodie - The first ever
Maxine 61 Cal-look bug - Cindy's daily driver.
Max - 73 standard Beetle hearse project - For sale
66 bug project - Real patina & Suby conversion
There's more, but not keeping them...

[Eric&Barb]