I have a 1979 bronco with a 351m with 4 barrel the guy before me unhooked a lot of the vacuum lines I need help to know where they go if anyone has a pic of their engine it would HELP A HOLE ALOT

 

I have found vacuum line routing to be a difficult topic to get a good answer on. I too have many vacuum line troubles due to PO. I have submitted many threads here about a need for some help but with so many variations and year to year difference it can be near impossible. The sticker under the hood might be all well and good but it just doesnt help when most of the components are no longer there. For now as long as you have the brake booster and dist. advance connected you should be able drive.

 

broncoon, here's a good pictorial of vacuum set ups on these engines..

78/79 Emission & Vacuum Diagram Picture Reference

 

Having trouble getting my 300 I6 to start when cold, what vacuum lines should I check? If I dump gas in crab it will start so I assume vacuum and spark are fine but need some ideas of where to go. Thanks

 

I would recommend you start a new thread on this as it is not related to the original post. But I will try not to leave you empty handed.

If your engine starts when you put gas directly in the carb, than it would lead me to belive you have a fuel problem before we can tell if you have a vacuum problem. Check your fuel line going into the carb, than inspect everything from the filter, to the mechanical pump on the side of the block, even check your lines coming from the gas tank and finally if no faults are found check your sending unit and internals of the tank.

Vacuum problems usually present themselves as a rough running engine, or high fuel consumption. give your engine a good look over, with the simplicity of a carb'd engine there are less components prone to failure. Hope this helped just a little

 

This happened to me when I first got my Bronco. It was due to a dying fuel pump. The diaphragm inside the pump was going bad, so it would allow gas to flow back out when it sat. It wasn't strong enough to get the fuel flow going for an initial start, but was enough to keep it running.