1970 Plymouth Valiant won't start!
 

Alright, so I've replaced the ignition switch and starter thinking it was an electrical issue.

I no longer think it is.

She wants to turn over. I have spark, and on more than one occasion I've gotten the engine to turn over. It seems to want to the most right after I install something new onto it. New starter, turns over. New fuel filter, turns over.

But now she won't, again.

When I took the old fuel filter off, it reeked of burnt hose. That's my only clue as to what the real problem is.

Some locals say the carb needs to be rebuilt, but that doesn't explain the smell.

Correction: first thing I replaced was the coil, not the switch.

So it .... Cranks? You have Spark? Check to make sure fuel is getting up to the carb and in the float bowl? If you pump the gas and look down the carb, you should see fuel squirt?

My apologies for my lack of proper vernacular (no sarcasm intended here). I'm new to all of this if that wasn't blatantly obvious, haha.

Yes on both counts.

I just found that the gap on the distributor is too small.

Worn Points will make it hard to start,,, :) Reset them and keep us posted... :)

So, I replaced the spark plugs, fixed the timing, and replaced the fuel pump (it wasn't dead, but it was pretty close). Same result.

I got sparks when I'd touch the battery connection on the alternator, so my guess is that there's a short somewhere there? But replacing the alternator shouldn't be associated with the vehicle's ability to turn over, right?

The only other thing I can think of is that there's a dead wire somewhere. I've replaced a lot of major electrical components, checked and charged the battery, and now the fuel pump just to be sure I was getting the proper amount of fuel to the engine.

I can't think of what else it could possibly be.

Do you have 12v at the + side of the coil with the ignition on?

And Where the old plugs wet when you took them out?
Is the carb squirting fuel when you pump it?

I'm only getting 6.5 on the coil.

The plugs weren't wet, but they did smell terribly of fuel. More on that in a moment.

The carb is not squirting fuel outside of where it should be if that's what you're asking.

Update: she lives. So, the last mechanic (I'm only the second owner of this magnificent beast. The first bought it new and, from what I'm told, only drove it to church and the grocery store) set the wiring to the spark plugs in reverse when they timed them last. I had the wiring fixed before I looked into why the wiring was set that way (they had it set that way because the timing was almost perfectly 180 degrees off). After realizing that and fixing the timing on the box itself, she fired right up. It's still a pinch off so I've still got to tinker a little more with it but at least she's firing now.

Now that she runs, I was considering putting some seafoam through the engine block directly from the air intake on the carb. Does anybody have any experience with that? She doesn't knock terribly right now, but I saw a LOT of build up inside the engine when I looked previously. I've seen the stuff work wonders on engines before, but not engines that were this old or had so many miles on them (she's sitting at I'm guessing 220k but I'd have to open up the dash to be positive and I don't really want to do that at this current time).

tl;dr - she's running, it was a spark plug timing issue. thoughts on running seafoam through the engine to break down build up inside the engine block?

Glad Y'all found the issue.... As for the Seafoam... I would just do the adding to the engine oil and adding it to the fuel tank... I dont think I would try to knock all the carbon off the top of the pistons at this point...