Topic: interesting situation today

[Jeffe 81]

...I was driving over Loveland Pass in Colorado today and my '81 pickup with 22r acted up.  It was cold and snowing, and at the elevation where the snow started sticking to the road, about 11,000 feet, it felt like the throttle cable was sticking.  Then about a minute later black smoke was coming out the tailpipe, the truck lost power, and died in the middle of the road!  So I rolled back and popped the hood.  I thought maybe the choke got stuck-not so.  Everything looked fine so I started the truck up.  It started right away as though nothing had happened and drove the rest of the 60 mile trip just fine.  The engine has 201,000 miles on it.  I recently tuned up the truck(plugs, wires, rotor, cap) rebuilt the carb and replaced the timing chain last year, and maintain the truck very well.  It was driving great before and after this, I'm just curious as to what happened.  What do you think?

[Duffil]

well, black smoke is fuel.  Sounds like it flooded out a bit, almost like the float needle stuck and then released...

[Marlin]

Do you have a 180 degree thermostat?
It sounds like the intake might of iced up just under the throttle plate.

When you let the engine sit, the intake heated up, and the frozen wet air/fuel mixture melted, and then the engine ran good again.

[79coyotefrg]

so that little electric heater  in my intake should be hooked up  when it gets cold

i can  maybe hook it up to a relay  and switch

[Willy Mammoth]

That could very well be it too. They have carb heaters on small airplanes to keep the carbs from freezing up.

You did say you were at 11,000 feet.

[Jeffe 81 [OP]]

Thanks for the responses everybody!  I was wondering if it was the carb icing up.  When I put on the headers I didn't install the small hot air tube.  I'll be putting it on for sure since it'll be much colder this winter!   

[Doosty]

i have drove mine at -40 C and not once have this problem? hmm


Yes, but at what altitude?

[rage]

now i could be mistaking, but isn't there a sensor of some sort that deals with carb mixture. that vacuum thing at the end of the air filter can that takes hot air off the exhaust manifold. when you start at low elevation engine runs good until higher elevation then runs rich. then you start it up at high elevation it runs good until you drop back down to normal elevation and it runs lean until you shut off and start again, then it runs fine. i know new cars do that but what about 80s' yodas?