1972 Beetle Cut off while driving.

[Marc]

4½" is barely acceptable for a tire wider than 165. Wider will fit, of course, but you do sacrifice some treadwall stability/handling, and lower pressures are needed to avoid early center-tread wear.
Ideally you should be running 5½ or 6" rims with those tires.

http://www.tire-information-world.com/r ... sizes.html

[rrb6699]

yea these are just temp tires while I'm restoring it. I increased air pressure and the ride is much better. like I said earlier the car is so light the tires barely wear anyway. ill be good till I can go to 5-bolt wheels.

[rrb6699]

update. been busy travelling. only remember to come out here if I get a msg thread.

the beetle still cuts off when I drive any significant distance, say 20 miles in hot weather, shut it off and if I dont wait like 30 minutes for it to cool down, the residual heat must cause (my guess) the coil to get overheated and it starts up but anywhere from .1 - '5 miles it will begin to lose power and cut off.

it could be vapor lock but why just in this situation? if, so, for these two issues I have one question for each:

coil: do they sell/mfr a high temp or harsh environment coil that can take heat well over what temps occur in 95 degree heat in the engine compartment?

if vapor lock how to prevent it?

thx,

[Piledriver]

For vapor lock, put an electric fuel pump up front and push.
I'm still betting its rust in the fuel tank clogging up the sock and then falling off.(or similar)
95 degrees won't kill a coil. Do make sure you are using the right coil, many need a ballast resistor.
Coil should measure ~3-4 ohms range, if less it may need a ballast.

Traditionally Bosch "blue" coils and stockers had a built in ballast resistor. (inside the can)
Bosch "red" coils needed a ballast or electronic ignition that allows setting dwell.

[rrb6699]

I cleaned the entire fuel tank out. also this only happens after driving in hot weather over 20 miles. in cool weather or otherwise never has this problem.

I would think fuel tank debris would be a constant issue not just when things get hot. I have a blue coil. 45kv?

manual fuel pump, weber 2bbl DFAV carb (single unit not dual syncs), pertronix electric ignition to replace the points.

I have a Carter electric fuel pump push unit 4psi but havent installed it because it doesn't look like theres any spot it will fit especially horizontally.

what else could be affected by heat?

[Piledriver]

Ah, Pertronix... Pop in a set of points and a condenser to troubleshoot, what you describe is one very common failure mode... Most common other than just dying outright.

Make sure there is a fuse on that black wire feeding the coil, too, early cars were unfused, falls under "great ways to burn down your car", as that unfused and usually krispy black wire is in the middle of the wiring harness... Sometimes it melts through to other wires. Really. New harness time, assuming it doesn't burn to the ground.

Also make sure to replace the grommet through the front tin for the fuel line, better---install a metal feed through.

I don't recall ever having any issues installing any electric fuel pump in a T1 up front by the brake line supports, on the flat bit at the bottom of the pan, passenger side, as the other side is fully occupied by master cylinder. (reverse if you are in UK) If you don't install rubber feet the clacker pumps make for a great audible "you're really outta gas" warning.
Not impossible at all, unless the pump is huge.

OTOH I have slept since then many, many times, about 20 years worth.

[rrb6699]

the main harness is new. head & taillight harnesses are original.ill have to check on fusing, but, would the pertronix overheat to cutoff untill it cools down? I know the coil is too hot to touch in these instances. I just have to sit there with hood open until I can start it again.

funny thing is I can ride 100 miles no problem but, if I cut the engine off (to fuel up or stop for a bite say) then start it and go you will almost always find me down the road about a half mile if I take off too soon.

I dont 100% understand vapor lock, but if somehow this is some sort of pressure build up that prevents fuel flow I think it makes sense. oh! important. maybe. im using an old oil cap from another vehicle that I fashioned for a fuel cap. it has tabs like the bug fuel cap had that I lost but does not seal tightly like the fuel cap should.

I have one on order.

rr

[Piledriver]

A 72 should have a charcoal tank evap can... this does not hurt performance, or economy, and is designed to vent pressure in the tank while minimizing fresh air entry. Any junkyard can supply something suitable, and a trip to home depot and a pet supply can provide the needed bits to roll your own for a few dollars.

I would be concerned about how hot the engine is, are all the seals intact/in place?
Underside air deflector tin all in place? (the ski jumps direct the hot air away from the car)

You have the correct decklid with vents?
Absolutely certain your timing is right and advance works properly?
Absolutely certain your TDC mark is TDC?
A swollen oil cooler does not cool properly, happens.

Too thick oil and/or oversize "heavy duty" pump can also drive oil temps through the roof.

I know decklid standoffs help greatly, but then you may need to fab a rain shield.(doable)

Pertronix can do weird things when they are dying, its easy to eliminate as the issue with a set of points and a condenser.
Consider putting them in a spare distributor, then the swap only takes a minute or so.

[rrb6699]

I addressed each below:

A 72 should have a charcoal tank evap can... this does not hurt performance, or economy, and is designed to vent pressure in the tank while minimizing fresh air entry. Any junkyard can supply something suitable, and a trip to home depot and a pet supply can provide the needed bits to roll your own for a few dollars.
i've seen this but ignored it. how can I make sure it's operating ok?

I would be concerned about how hot the engine is, are all the seals intact/in place?
Underside air deflector tin all in place? (the ski jumps direct the hot air away from the car)

-ill check these all out. thx]

You have the correct decklid with vents?

-yes]

Absolutely certain your timing is right and advance works properly?

yes]

Absolutely certain your TDC mark is TDC?

-well, I used the mark and aligned it with the seam. thing is when I took the rotor off the rotor wasnt pointing to #1. so I rotated the rotor to point at #1. wrong... had to re-align the timing mark after I rotated the rotor back to the the mark I made before I rotated it. it runs with good power and idles fine. very smooth.

A swollen oil cooler does not cool properly, happens.

don't know how to checkvthis. I put an 8-pass oil cooler behind the shroud with an oil filter.

Too thick oil and/or oversize "heavy duty" pump can also drive oil temps through the roof.

I use 10w-40 oil. seemed like it was the right choice for hot weather.

I know decklid standoffs help greatly, but then you may need to fab a rain shield.(doable)

not sure I want to do this. can I add an air scoop (sm) u front and maybe pipe ar into the engine compartment?

Pertronix can do weird things when they are dying, its easy to eliminate as the issue with a set of points and a condenser.

- I like the electronic ignition. would the pertronix shutdown if it got too hot?

Consider putting them in a spare distributor, then the swap only takes a minute or so.

thanks much

[Piledriver]

...OK, that explains everything.

You replaced the doghouse cooler, which dumps its hot air outside the engine compartment, with one that feeds the engine hot air.

I think everyone tried that once.
It was Not A Good Idea.

Those adapters actually have a good use, but hooking an oil/filter cooler loop to it as intended isn't it.

Put a dog house cooler, proper fan and shroud etc together correctly and do the oil filter properly, off a plugged oil pump with a full flow cover, or get a cb pump with the in and out fittings.

You have set up what FJCamper once called "faux flow filtration", it only works when the oil cooler does.

I still strongly suggest trying the points or at least carrying a spare, but at least we know why you are running hot.

[rrb6699]

ah ok. I didn't do the cooler myself. it was done by the previous owner. I'm not sure if they removed the original cooler. they may have added it. is there a way to flush out the oil system with some sort of pressurized feed in case there's a restriction?

i've been driving this car for awhile now and it never had this problem before with this setup. Oh. there is one thing I didn't mention. I had my nephew change the oil and he didnt change the filter. he didnt have one and when he asked me I told him put the old filter back on and I would put one on, but, forgot.

I didnt think nothing of it but it could be restricting oil flow. I'm gonna change the oil today myself. I think this may help. do you think a viscosity of 10w-30 would help?

I dont want to flush the system with additives as I tried them before with this bug and it doesn't seem to respond well to them in fuel or oil. do synthetic oils cool better?
I haven't tried Mobile1 with this car.

even with everything discussed I still can't identify which component(s) are failing with the heat.

[madmike]

Is to coil getting hot? if so try swapping it

[rrb6699]

well, too hot to touch. I'm going to fashion an airflow from the front through a punchout up front and run it into the engine compartment. I can drop the temp some plus focus air on specific components well enough to maybe isolate the problem component.