1972 Ford Bronco 302 4wd possible vacuum hose issue

[XXFISHER1XX]

My Bronco broke down today. When it failed, it seamed as if it ran out of gas, 5 min from home. I waited an hour for roadside to deliver, and it started and ran long enough to get back home. I noticed a loud ish hissing noise from the back part of the engine, and found a hole that looks like there should be a hose attached to it. I covered it with my finger and it was sucking air. After it sits for a while, it will start back up and die again shortly after.

http://i.imgur.com/ejtQwy2.jpg

 

[Justafordguy]

If you don't have power brakes you need to block that hole off. If you have power brakes you should have a hose going from there to the booster. Sometimes if the engine backfires through the intake it will blow those caps off.

 

[Rustytruck]

It probably had a rubber cap on it and it split and fell off. If you notice you have several rubber caps back there all splitting waiting to take the same path. I notice the capped off EGR port. This Bronco engine had a bunch of emissions related crap that have been taken off which is why you have all these capped vacuum lines. Replace that cap and carry a few extras as they only last a couple of years. Once you get more familiar with your Bronco you can replace some fittings and eliminate these ports that are just capped like that. That will go along ways to make the truck more reliable. Its not good to be driving an engine with vacuum leaks.

 

[surfer-b]

The next time it does this remove the air cleaner, look down the carb and work the throttle linkage, with engine off, you are looking for gas squirting from the nozzles, if no fuel remove the fuel line an see if its running dry. You can place the line in a bottle and turn the motor over a few times to see if the fuel pump is working, also check the fuel selector valve if there is one. It could even be the sock on the fuel pickup in the tank. You are just gonna have to start eliminating things one at a time, it may not even be fuel. Rustytruck nailed on those vacuum caps, they need to be replaced.