Help me brainstorm this issue

[oxsign]

‘71 Squareback starts, warms up then shuts off and won’t start again for a couple hours. When I say shuts off, I mean it shuts right off like the key was turned off suddenly. I can try to start it again but it’ll just crank and not start. In the last week I have installed all new coil, points, condenser, distributor, cap/rotor & starter. The motor is a 1776 with dual 40s. Maybe bad ignition, relay, something else? Is there a way to test those things?

Ideas?? Thanks for any/all help.
_________________
1971 Squareback, fully bagged, 1776.
Build thread here.....
https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

[GMendoza]

Are you getting spark? You can check with a timing light

[Ossipon]

Until you said what carbs you had, it reminded me of a problem I had on a 34PICT-3 years ago. It had a loose internal connection on the Electric cutoff switch. It had exactly the same symptoms, but mine would run for a bit longer. Once I replaced the cutoff with a pilot jet, the problem immediately disappeared. My hunch is something in your system cutting off fuel flow.
_________________
Ossipon
VWs in my life:
Air
Type 1 - 59, 62, 63, 71 Super 68 KGhia/ Type 2 - 59 Single Cab / Type 3 - 64 Notch
Water
GTI 83, Jetta 81, 85, 87, 91 TDI, 98 TDI, 09 / New Beetle 99 / SportWagen 05, 13 / Tiguan 18 / T3 92

[raygreenwood]

Check your fuel tank venting to make sure you are not pulling a vacuum.

Ray

[Qldelsie]

He said "it shuts off suddenly, like the key has been switched off".
Surely a fuel restriction would cause it to splutter a bit before it died ?
Sounds more like electrical to me.........

[raygreenwood]

[Bobnotch]

[veedweeb]

I had a similar problem with my old Square a few years ago.

After a lot of searching, I found that the trigger wire from the coil for the rev counter that I'd fitted was intermittently shorting out on the bodywork and that was just shutting the ignition off instantly.
_________________
1963 Turbo WBX Bug
2000 Sedan Clasico Mexican Bug
1972 Type 3 Squareback

[raygreenwood]

Had to re-read for clues.

The other issue .....is the fact that it....... "wont start again for a couple of hours".....

If this is consistent.....and it ALWAYS starts again after a couple of hours......I am still going back to a fuel problem and not an electrical problem.

If it were electrical....like a ground heating up or vibrating until it breaks.....still possible.....but doubt that it would consistently re-start like clockwork.

Either its flooding.....and takes a couple of hours to evaporate fuel

Its choked off with silt in the tank pick up tube area.....not uncommon and it can take a,while for line fuel slowly flowing back to rinse silt out of the way.....

Or you are pulling a vacuum on the tank.

Try these things:

Remove the gas tank cap, start snd warm up. If the problem disappears.....ots a tank venting issue. If it does not help......try pouring a little fuel into both carbs and try to re-start. If it works.....your float heights are wrong, fuel is getting restricted to the carbs (could be silt, could be the pump, could be a range of carb problems).

If that does not help....look down the top of the carbs to see ir they ard wet and pull a spark plug from each side and see if they are wet.

Ray

[oxsign]

Really sorry for not replying here. I never got any notifications of your replies, sorry.

So after all this it turns out to be a fuel issue. More specifically, the lining/seal the previous mechanic did. As you can see from the pix, it’s just coming apart inside and clogging things up.

Today I got a 2gal can and a new pump. I ran a hose from the pump to the cab and it ran flawlessly. Drove it around the block a couple times and had zero issues. So today I drained and removed the tank. I’ve reached out to a couple people in the FS section but no one seems to want to ship a tank to FL. I may look in to having a fuel cell made for it if I can’t find anything local.

_________________
1971 Squareback, fully bagged, 1776.
Build thread here.....
https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

[Bobnotch]

[oxsign]

[Clatter]

Many radiator shops will boil out a fuel tank.

Or you could fill it with paint remover and nuts/bolts and slosh it around or something?

With the right application of heat/chemicals/agitation the stuff will come out.
_________________
Bus Motor Build

What’s That Noise?!?

[oxsign]

[Erik G]

ask Chadd - his number is in this ad https://www.thesamba.com/vw/classifieds/detail.php?id=2366674

[raygreenwood]

If it has no actual holes in it......have it caustic washed at a radiator shop which will remove all of the liner and varnish deposits. Then acid wash it. That will literally dissolve all rust down to metal. If it still has no leaks or pinholes....proceed to next stage.

Then let it flash rust for a couple of days after rinsing it out. Then pour in a quart of Ospho or similar about a pint at a time. Fully agitate to cover every surface . Drain it. Do not rinse it. Let it dry for a full 24 hours someplace warm. This converts the surface rust to black iron phosphate
Done.

Keep it full of fuel and it will likely not rust again until after you are dead from old age.

Well established method.

Ray

[oxsign]