So I just drove 1,200 miles, and now my Falcon won't start.

[1968 Falcon]

I'll give a little back story in case that helps anyone understand what may be going on...
I just drove my 1968 Falcon with a 200 six from Denver to Los Angeles over the past three days, and arrived last night. When I got here to lower elevations I noticed that the engine was running a little rough and there was a little bit of knocking if I floored it at high speed, but I didn't bother to try to problem solve it last night. This morning I set the timing back to about 9 degrees (I think I had it at 10 before, but I'm not sure) and turned the mixture screw back out about 1 turn so the engine was running smoothly and quietly again like it had been before I went down in altitude. I shut it off, and when I tried to start it again a few seconds later I heard a quiet "pop" and I had to hold the gas pedal down part way for it to stay running. Now the engine either acts like I'm giving it full throttle, or none at all and it dies. It dies if I give it less than 1/4 pedal, and if I hold it any further it acts like I'm flooring it.

I don't know where to start looking. And I'm 1,200 miles from home, and yes, I am stupid for trying to take this car that far and back.

 

[xctasy]

Spark, fuel, then detail.

Unhook one one spark plug from the head, then rehook it to the wire, resting on the metal part of the block, head, rocker cover. Is there spark?

If not, check contact breaker, should be set a fingernail appart when the hexangonal rotor cam lifts them six times each turn of the distributor.

If that's okay, Replace the coil, Check rotor and cap.

Old coils are a real issue and can cause problesm, so can condesors. So can hi tension leads.

If you are able to borrow a compression gauge, that will help.

At the same time, fuel delivery must show through the main jet on attempting a start up, so have an assistant push the accelerator down, and look down the carb to check that fuel is squirting, with the engine off of course.

 

[1968 Falcon]

My knowledge is very basic, especially when it comes to the ignition system. I've basically groped my way through the dark when it comes to keeping this car running, so there are a lot of "common knowledge" type things that I just don't know. I don't really know what the contact breaker is or the condenser. When it comes to the distributer itself, I don't even know how to set the points. So I'm a bit wary of just blindly experimenting lest I screw anything up more.

EDIT:

WAIT! I've got it running again, a hose that leads from the base of the carburetor to the top rear end of the valve cover had come loose. But just in the spirit of continuing my quest for knowledge, what is that hose?

 

[bubba22349]

That's a vacuum hose to the PVC valve being loose or off would be a giant vacuum leak. Glad you found it maybe you should pick up a new hose clamp at a auto parts house

 

[1968 Falcon]

Thank you very much both of you!

 

[woodbutcher]

Outstanding.The way that I always set the ignition points IF a feeler guage was not available was to use the cover of a match book.Paper matches that is.
Good luck.Have fun.Be safe.
Leo