'73 Beetle Dies at Random??

[NSG-Garage]

Hey alls...

New to the forum. Have a bit of a head scratcher with my '73 beetle.

Got the car non-running. Original carb was shot so replaced it with an EMPI 34 pict 3. Got it running but had a pretty hard stumble off idle. After doing some digging, ripped the knock off 009 distributor out and replaced it with a Petronix SVDA replacement. Set timing at 30 degrees at 3k rpm.

Went on and went through the rest of the ignition system... replaced all the wire ends that were a bit frayed around the coil... new bosch blue 3.4 ohm coil... new bosch plug wires and NGK plugs. Fully serviced the car out and adjusted the valves. Car runs like a top.

BUT.... at random, while driving, it will act as if I reached up and turned off the key. Car just dies. No stumbles.. no sputters... no popping or backfiring... nothing... the pedal just goes dead and it coasts to a stop. Still getting fuel. Now sometimes it will start right back up... other times, it wont. It took roughly 100-150 miles for this to start happening. Fan fantastic for the first 100 -150 miles.

The last time it did this, I was 40 miles from home. Had a friend come flat tow me home... by the time we got to the house, it fired right back up and ran great. Let it idle in the driveway for half an hour and it died again. Pulled the distributor cap and there was a black dust on top of the rotor. Wiped it off and it fired right back up and was fine for another 100 miles or so.

Today, I left the house... got 5 miles or so and bam... dead again. Still cranks great... If i mess with it much, it will start smelling strong of fuel so I know its still getting fuel... Still getting good voltage to the coil when I test it right after it dies (matches battery voltage). Released the fuel cap just to make sure it wasn't pulling a vacuum on the tank or something... no change (no noise when I cracked the cap either).

Any idea? Maybe something wrong with the Petronix electronic ignition module? Has less than 300 miles on it. From the research I'd done on it, most people like their stuff and don't have many issues with them. I will say that the vacuum canister was bad on this one out of the box... but I was under the impression that these electronic modules either work or they dont... no real in between.

I've blown out fuel lines... cleaned the fuse block and replaced all the fuses with german ceramics... It's almost acting like fuel either completely shuts off or the ignition completely dies. Sometimes it will fire right back up.... other times, it will be a few days of tinkering with different things and suddenly it'll start right up as if nothing happened.

Sorry for the long first post... but I'm not sure what I'm missing.

[busdaddy]

Do any dash lights illuminate when it dies?, even for the brief moment as it's coasting to a stop, before you push the clutch or put it in neutral?
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[NSG-Garage]

Not that I've had a chance to notice. After a few seconds, both the gen and oil pressure lights are on as if just cycling the key to the run position.

[jinx758]

Hmmmm ... odd

Just some may_beez :

Clean ALL grounds ... battery posts, battery to frame, & both sides of transaxle grounding strap

Worn or dirty electrical portion of ignition switch

Vapor lock

Gas tank not venting

Idle solenoid bad

Condenser bad

Points pitted ( Pertronix magnet pick-up too far or close to reluctor ((thingy)) )

Dirty /loose connections of wiring in engine bay

Pin not seated on float in carburetor (I've had that)

Dirty fuel filter or sock in fuel tank

Bad gas - water in gas

Sticking advance weight / springs in distributor

Bad coil

Loose distributor clamp

Unseated coil to distributor plug wire
(I've had that)

Fuel pump rod sticking (if mechanical)

Tighten loose nut behind steering wheel
(oh wait, that was my problem)

I truly hope you thoroughly cleaned tha EMPI carb & set the float level as no carb ever runs optimally out of the box ... unless it has been the capable hands of a quality refurbisher.


Truthfully it does sound electrical somewhere but I put some other things out there using my Redneck Engineering Degree from the University of Shadetree Mechanics Institute.

Best of luck !

stay safe ... jinx
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" It's not valuable unless you learn something from an experience. " Henry Ford

It's not unlike the same difference

You can't push a rope


VALVES (cold)
POINTS
TIMING
CARB (fully warmed engine)

SCRAPE ALL GROUNDS

My Craigslist rescued 100 footer :
1971 Standard Bug
1776cc dual port
034 distributor
38mm EGAS Carburetor

[Starbucket]

The electrical part of your ign. switch has died, to test run a jumper from the battery + to coil + use the ign. switch to start and drive, if the problem has gone away, you found the problem (remove jumper to stop motor) and replace the electrical part of ign. switch.

[runscx]

My 74 super did something similar, was driving just fine then died, cranked and cranked and no dice.

I was told by a vw mechanic to smell the oil off the dipstick for gas, yup it had a hint of gas, he said go to the back of the carburetor and where the gas line goes in tap on the top of the carb.

Tapped on it, sounded like I heard something. Was told to go back in the car step on the gas pedal full throttle and crank it.

Bada Bing Bada boo, it fired up after a sputter or two and ran like a champ!

Apparently theres something that got stuck back there, its an Empi Carb as well.

I pointed to where I tapped on it with a small hammer. You have to take the air filter housing off to get to it when its on your engine FYI.

You can imagine my relief being 4 hours from home when it happened.

I've since bought a solex carb and keeping the Empi for back up.

[NSG-Garage]

Thanks for the list of things to check.

I'm going to pull the top of the carb here in a few days when I get a minute and clean it out. I'm also strongly considering replacing the ign. switch (electrical) although I did try to start it with a hot jumper to the coil with no change.

We'll see what I find in the next few days.

Pertronix is sending a new module also.

[NSG-Garage]

Got my ignition problem sorted out finally.

After waiting for 3 weeks to hear from Pertronix, I was able to talk Amazon into letting me return the distributor for a refund.

Then I found www.vwnos.com and ordered one of his reman Bosch 034 distributors. They are ultrasonic cleaned... rebuilt with all bosch oem parts (got the bosch cap and rotor too).. and setup on his SUN test bench.

He emailed as soon as I ordered it letting me know it would be a few days. Arrived well packaged. Dropped it in... fired it up. Set base timing to 7.5... checked full centrifugal advance which was right around 30 at 3500rpm.

This thing runs better than it ever has. Super smooth power transitions... takes off super smooth... stab the throttle at any time and it just goes. No hesitation.. no stumbles. Now holds a smooth 900rpm idle with no stumbles.

Yup... Bosch is the way to go when you can find them.

[Cusser]